Is Pertussis Contagious? Symptoms and Treatment Explained

On By Dr. Scott RennieIn Infectious DiseaseLeave a comment

Pertussis, or whooping cough, made a comeback in 2024. Outbreaks were reported in different regions around the world, and the United States was no exception, with cases rising for several years running despite decades of vaccination effort, and in 2024 there were more than 35,000 reported cases, higher than what we’d typically seen over the prior decade. Some of that traces to waning vaccine immunity, incomplete vaccine schedules, and vaccine hesitancy. Schools were a particular hotspot, especially among older children and adolescents who had missed boosters.

This isn’t a new story. In the early 20th century, pertussis was one of the leading causes of death in children. In the 1920s and 1930s, hundreds of thousands of cases occurred every year in the U.S., and fatality rates in infants sometimes reached 5 to 10 percent. Families often saw multiple children get sick at the same time. Hospitals had few tools to help. No antibiotics. No vaccines. Isolation was the only real measure available, and it wasn’t enough.

The arrival of the first whole-cell vaccine in the 1940s changed the picture, and by the 1950s and 60s, pertussis cases had dropped by more than 90 percent. It went from a routine killer to something most doctors rarely saw. But the drop didn’t mean it disappeared; over time, as immunity fades and vaccine uptake slips, the disease resurfaces.

What Pertussis Does in the Body

The cause is Bordetella pertussis, a gram-negative bacterium discovered in 1906. It attaches to the airway lining using adhesion proteins and releases toxins that damage the respiratory tract and disrupt the immune response. Pertussis toxin, adenylate cyclase toxin, and tracheal cytotoxin are some of the key players, and together they paralyze cilia, create thick mucus, and inflame the airways. That’s what sets up the violent coughing fits and the difficulty clearing secretions.

The incubation period is usually 5 to 10 days but can stretch out to 3 weeks, and transmission is mainly through droplets when people cough, sneeze, or talk, though it can also spread indirectly through contaminated surfaces.

The Course of Illness

Pertussis has three stages. The first, the catarrhal stage, looks a lot like a cold. Patients may have mild cough, runny nose, and low-grade fever. But this is also the most contagious stage, and infants in this stage can suddenly stop breathing or develop pneumonia.

After one to two weeks, the paroxysmal stage begins, the coughing fits severe, sometimes so prolonged that patients vomit or become exhausted. The classic “whoop” happens when the patient forcefully inhales after running out of breath. This stage can last weeks.

Finally comes the convalescent stage. Symptoms ease, but the cough may linger for months, and infants are at the highest risk of complications throughout, including pneumonia, seizures, and encephalopathy.

How Long People Are Contagious

Without treatment, a person with pertussis can remain infectious for weeks, often up to three weeks into the paroxysmal stage. With antibiotics, contagiousness drops significantly after five days of therapy.

Diagnosing Pertussis

Clinical suspicion is usually the first step. The cough pattern and exposure history often give it away. PCR testing is the most rapid and sensitive diagnostic method now, while culture is still considered the gold standard, though rarely used because it takes longer and needs special media. Serology may help later in the illness.

Treatment and Timing

Macrolides like azithromycin are first-line treatment, with trimethoprim-sulfamethoxazole an option if macrolides can’t be used. Antibiotics are most effective early, ideally in the catarrhal stage, but they’re still useful later to limit spread.

The CDC recommends treating patients within three weeks of cough onset if they’re over a year old, within six weeks for infants under one, and also within six weeks for pregnant women close to delivery. Supportive care, hydration, rest, and monitoring, is especially important for infants, who may need hospitalization.

Post-Exposure Prophylaxis

Preventing spread matters just as much as treating active cases, and giving antibiotics to close contacts can stop the chain. This is particularly recommended for infants under 12 months, pregnant women in their third trimester, and household members or healthcare workers exposed to confirmed cases. Timing matters: post-exposure prophylaxis should start within 21 days of exposure.

Prevention and Vaccination

Vaccination is still the strongest defense. The childhood DTaP series provides good protection early on, though immunity fades over time. About 98 percent of children are immune one year after their last DTaP dose, but that drops to around 70 percent five years later. That’s why boosters are needed.

The Tdap booster is given at 11 or 12 years of age, again in adulthood every 10 years, and during each pregnancy between 27 and 36 weeks. Protection from Tdap is estimated at about 73 percent in the first year and 34 percent after four years. This waning immunity is a major factor in outbreaks.

Public health responses focus on quick recognition, isolation of cases, prophylaxis for contacts, and community education, and mask use, hand hygiene, and cleaning surfaces all help reduce spread.

Why Vigilance Matters

Pertussis is not a disease of the past. It’s resurging in part because immunity doesn’t last forever, and physicians need to recognize it early and treat aggressively, while patients and families need to keep vaccination schedules up to date. When that doesn’t happen, infants and medically fragile patients pay the highest price.

—

Scott Rennie, D.O.
Board Certified in Obesity Medicine and Family Medicine

This blog is for educational purposes only and does not constitute individual medical advice. Always consult your own physician before making changes to your health, medications, or treatment plan.

Sources

  • Centers for Disease Control and Prevention. Pertussis (Whooping Cough). https://www.cdc.gov/pertussis
  • Cherry JD. The science and fiction of the “resurgence” of pertussis. Pediatrics. 2003;112(2):405-406. PMID 12897292.
  • American Academy of Pediatrics. Red Book: 2021–2024 Report of the Committee on Infectious Diseases.
  • Clark TA. Changing pertussis epidemiology: Everything old is new again. J Infect Dis. 2014;209(7):978-981. PMID 24626532.

Norovirus Illness: What Patients and Doctors Need to Know

On By Dr. Scott RennieIn Infectious DiseaseLeave a comment

Every winter we brace for an uptick in norovirus, often dismissed as the “stomach flu.” For many, it’s just a miserable few days of vomiting and diarrhea. In reality, norovirus is a major public health issue: it spreads quickly, it’s hard to kill, and outbreaks can overwhelm entire communities.

Norovirus is part of the Caliciviridae family and is the leading cause of acute gastroenteritis worldwide. A single infected person can trigger dozens of cases. It doesn’t take much. Just 10 to 20 viral particles. The virus survives on surfaces for days, resists alcohol-based sanitizers, and tolerates a wide range of temperatures, which is why schools, nursing homes, cruise ships, and restaurants are common hotspots.

Symptoms and Impact

Illness usually starts suddenly. Patients may complain of nausea, stomach cramping, watery diarrhea, or repeated vomiting. Children often vomit more, adults tend to have more diarrhea, and fever, fatigue, and body aches can happen but aren’t always present.

For most people, symptoms last 1 to 3 days. But dehydration can become serious, especially in infants, older adults, or those with weakened immune systems. Years ago, in hospital-based practice, I admitted patients who couldn’t keep fluids down and needed IV hydration after only 24 hours of illness.

How It Spreads

Norovirus has been called the “perfect pathogen” because it finds so many ways to move from person to person. Direct contact with someone sick, eating contaminated food like undercooked shellfish, drinking contaminated water, or simply touching a door handle can all spread infection, and even vomiting can aerosolize tiny droplets of virus into the air, which is why outbreaks in crowded dining halls or cruise ships often expand so rapidly.

The incubation period is short: just 12 to 48 hours. That means someone can be exposed at a group gathering and have symptoms by the next day. Diagnosis is usually clinical during outbreaks, though lab confirmation with RT-PCR testing is reserved for severe cases or public health investigations.

Treatment

There is no antiviral medication for norovirus. Management is entirely supportive. Oral rehydration is the first step, with IV fluids for those who can’t keep liquids down, and ondansetron can help control vomiting in children and adults, though it doesn’t shorten the course of illness. A bland diet and gradual return to regular foods is usually recommended. Antibiotics don’t help, since this is viral.

Prevention

Preventing norovirus is about breaking the chain of transmission, and handwashing with soap and water works better than alcohol-based sanitizers. Surfaces contaminated with vomit or stool should be cleaned with bleach-based disinfectants, because many common cleaners aren’t effective. Shellfish should be cooked thoroughly and produce rinsed before eating.

Infected people should stay home for at least 48 hours after symptoms end, since viral shedding can continue. During outbreaks in schools or long-term care facilities, early recognition and strict cleaning protocols are what actually stop the spread, not treatment after the fact.

Why It Matters

Norovirus keeps proving how disruptive a “simple” virus can be. Cruise ships diverted from ports, schools shutting down for deep cleaning, long-term care facilities under quarantine, these are all real-world consequences. Each outbreak is a reminder that prevention matters as much as treatment.

For patients, the focus is on hygiene, hydration, and staying home when sick. For healthcare providers, it’s about rapid recognition, supportive care, and education, and for public health officials, the job is surveillance and outbreak response. Together these steps limit how far norovirus reaches.

—

Scott Rennie, D.O.
Board Certified in Obesity Medicine and Family Medicine

This blog is for educational purposes only and does not constitute individual medical advice. Always consult your own physician before making changes to your health, medications, or treatment plan.

Sources

  • Centers for Disease Control and Prevention. Norovirus. https://www.cdc.gov/norovirus
  • Hall AJ, et al. Norovirus disease in the United States. Emerg Infect Dis. 2013;19(8):1198-1205. PMID 23876403.
  • Glass RI, Parashar UD, Estes MK. Norovirus gastroenteritis. N Engl J Med. 2009;361:1776-1785. PMID 19864676.
  • Atmar RL, Estes MK. The epidemiologic and clinical importance of norovirus infection. Gastroenterol Clin North Am. 2006;35(2):275-290. PMID 16880066.

H5N1 Bird Flu: What Every Patient Should Know Today

On By Dr. Scott RennieIn Infectious DiseaseLeave a comment

As physicians, we try to keep an eye on infectious diseases that might pose broader risks. H5N1, also called highly pathogenic avian influenza or bird flu, remains one of those, and the virus mainly infects birds but has crossed into humans with severe outcomes. The first human cases were seen in Hong Kong in 1997. Since then, human infections have been sporadic, usually tied to direct contact with infected poultry or contaminated environments, and unlike seasonal influenza, it doesn’t spread efficiently from person to person.

WHO’s cumulative count puts the case fatality rate at about 52 percent, 463 deaths among 888 confirmed cases worldwide since 2003, in data current as of March 2024. Human cases identified in the United States during the 2024 dairy and poultry outbreak ran far milder than that historical average, and many were mild. But the potential for severe disease is still there.

Recent Human Cases

In the United States, poultry wasn’t the only exposure route. In March 2024, transmission from cows to humans was confirmed, and cats were infected too, after drinking raw milk from infected cows. Between March 28 and October 31, 2024, there were 45 human cases in six states, all in adults, 25 linked to infected cows and 20 to poultry. By January 2025, there had been about 90 reported human cases nationwide.

A common thread was inconsistent use of protective equipment, and infection rates ran higher when gloves, masks, and goggles weren’t used consistently. Among those infected during the March-October window, 71 percent reported wearing gloves, 60 percent eye protection, 47 percent face masks, and only 36 percent reported both eye protection and masks together. PPE seemed to make a real difference, but adherence was incomplete.

Symptoms

The most common presentation was conjunctivitis. About 93 percent of patients developed viral pink eye, and fever was reported in about half, with headaches and muscle aches close behind. Sore throat, cough, and fatigue were less frequent. Diarrhea and nausea were rare. The median duration of symptoms was four days. Severe disease can still progress quickly to respiratory failure, multi-organ involvement, and death, though fatality figures reflect real biases in surveillance and reporting, since mild and subclinical infections are the ones most likely to go undetected.

Diagnosing H5N1

Diagnosis depends on history and testing. Exposure to poultry, cows, or contaminated settings should raise suspicion in anyone with severe flu-like illness. Nasopharyngeal or conjunctival swabs are typically used. PCR testing is the gold standard. Culture is rarely done. Biosafety concerns. Serology is sometimes used for retrospective surveillance.

Monitoring and Management

Close surveillance is essential for people exposed to infected birds or animals, with daily checks for fever and respiratory symptoms during the incubation period, about 10 days, recommended. Public health reporting remains critical for containment.

Treatment relies on antivirals like oseltamivir or baloxavir if started early, and severe cases often require oxygen therapy or mechanical ventilation, with supportive care for complications like ARDS central to management.

Human-to-Human Spread

What keeps H5N1 from being a global pandemic threat is the lack of efficient human-to-human spread. There have been family clusters and caregiver cases, mostly in the mid-2000s, where limited transmission was suspected, including a mother in Thailand caring for her sick daughter and family members in Indonesia in 2006, cases that involved close, unprotected exposure where the virus didn’t transmit beyond those immediate contacts.

H5N1 lacked the genetic adaptations that would make it easily transmissible like seasonal flu or COVID-19, and the concern was that mutations or reassortment with human influenza strains could change that, which is why surveillance continued.

Where the Risk Stands

As of early 2025, the risk to the general public remained low, with most cases stemming from direct animal exposure and person-to-person spread limited. For clinicians, though, awareness matters: we need to consider H5N1 in patients with severe respiratory illness who also have a relevant exposure history. For patients, the focus should be on minimizing contact with infected poultry, avoiding raw milk, and following public health guidance on protective measures.

H5N1 was still circulating in birds, and occasionally in other animals, and it occasionally infected people, though it was not, at that point, spreading widely between humans. The threat was real but contained. The critical piece remains vigilance: watching for changes that would signal the virus adapting toward easier human spread.

—

Scott Rennie, D.O.

Sources

Garg S, Reinhart K, Couture A, et al. Highly Pathogenic Avian Influenza A(H5N1) Virus Infections in Humans. N Engl J Med. 2025;392(9):843-854. PMID 39740051.

Centers for Disease Control and Prevention. Avian Influenza A (H5N1) Virus. https://www.cdc.gov/bird-flu/situation-summary/index.html

World Health Organization. Avian Influenza Weekly Update. https://www.who.int/emergencies/disease-outbreak-news

Uyeki TM, Peiris M. Novel Avian Influenza A Virus Infections of Humans. Infect Dis Clin North Am. 2019;33(4):907-932. PMID 31668198.

Board Certified in Obesity Medicine and Family Medicine

This blog is for educational purposes only and does not constitute individual medical advice. Always consult your own physician before making changes to your health, medications, or treatment plan.

Human Metapneumovirus (hMPV): What You Need to Know

On By Dr. Scott RennieIn Infectious DiseaseLeave a comment

Human metapneumovirus, or hMPV, doesn’t get the same attention as influenza or COVID-19, but it’s worth understanding. It was first identified in 2001, though genetic studies suggest it has circulated for decades, and it’s a member of the Paramyxoviridae family, the same family that includes RSV.

Transmission is through respiratory droplets. That means coughing, sneezing, or close contact with an infected person is usually how it spreads, and anyone can get it, though young children, older adults, and people with weakened immune systems are most vulnerable to severe illness.

Where It Shows Up

hMPV is found worldwide. It circulates throughout the year but tends to spike in late winter and spring in temperate regions, and improved diagnostics over the last two decades have shown just how common it is. Clusters show up in schools, childcare centers, nursing homes, and hospitals. Often alongside influenza and RSV activity.

In the United States, the CDC tracks it as part of routine respiratory surveillance, and globally, WHO lists it as one of several viruses contributing to seasonal surges of respiratory illness.

Symptoms and Overlap

The symptoms of hMPV are familiar. Patients may have fever, cough, sore throat, congestion, fatigue, and sometimes wheezing, and in healthy people, illness usually resolves within one to two weeks. In infants, older adults, or immunocompromised patients, the disease can progress to bronchiolitis or pneumonia.

The overlap with RSV, influenza, and COVID-19 makes it nearly impossible to identify clinically without testing, and in practice, we often don’t test unless patients are hospitalized or part of an outbreak under investigation.

Why It Matters

Most patients recover with supportive care. But hMPV deserves attention for a few reasons: high-risk populations can become severely ill enough to need hospitalization. Unlike flu or COVID-19, there’s no vaccine and no specific antiviral, so care stays supportive: oxygen, fluids, symptom management. And hMPV adds to the seasonal burden on the system overall, and when it circulates alongside RSV and flu, pediatric and ICU beds can fill fast.

Current Reports

China had reported more cases the previous winter, mostly among children under 14 in northern provinces. The increase triggered heightened monitoring at the time, though local health authorities noted the pattern was typical for the season and not as severe as the same period the year before. The WHO emphasized that hMPV is a known virus, not a new or emerging threat, and said it did not represent a global health emergency.

What To Watch For

For physicians, it comes down to clinical awareness. If a patient has unexplained respiratory illness, especially if they’re very young, older, or immunocompromised, consider hMPV in the differential. For patients, the message is simple: good hygiene matters, and wash hands, avoid close contact when sick, and stay home if you’re symptomatic. These are the same steps that help reduce spread of other respiratory viruses.

hMPV doesn’t carry the same weight as influenza or COVID-19, but it plays a consistent role in seasonal respiratory disease, and understanding it helps us manage patients more effectively and prepare for the extra strain it can place on hospitals during peak months.

—

Scott Rennie, D.O.
Board Certified in Obesity Medicine and Family Medicine

This blog is for educational purposes only and does not constitute individual medical advice. Always consult your own physician before making changes to your health, medications, or treatment plan.

Sources

Managing Insomnia and Sleep Problems: A Physician’s Perspective

On By Dr. Scott RennieIn Other Diseases and ConditionsLeave a comment

Insomnia is one of the most common problems I deal with. A few bad nights bleed into everything: work, mood, patience, appetite. Patients usually open the visit asking about pills or supplements, and I understand why. Sleep feels like something that should have a switch. Most of the time the answer is duller than a prescription and works better, which is a hard sell at nine at night when someone has been staring at the ceiling for a week.

How Much Sleep Do We Need

Seven to nine hours suits most adults. Under six on a regular basis carries real risk, and routinely running past nine is its own signal that something else is going on. The exact number moves from person to person, and I put more weight on how someone functions at four in the afternoon than on the number they report.

What Sleep Actually Does

Sleep is repair time. It consolidates memory, sharpens focus, and steadies the emotional baseline, which is why a rested person absorbs a bad day and a chronically tired one doesn’t. It supports immune function, cardiovascular health, and metabolic balance. The long-run associations with longevity and lower rates of chronic disease are consistent enough that I treat sleep as a vital sign rather than a lifestyle detail.

The Cost of Short Nights

Chronic sleep loss shows up in obvious ways and quiet ones. Fatigue, irritability, work that slips. Those are the complaints people bring. What they usually do not connect to sleep are the things that accumulate over years: hypertension, diabetes, heart disease, obesity. Immunity weakens, which is why the poor sleepers in a household tend to be the ones who catch everything going around. Anxiety and depression travel with chronic insomnia in both directions, each making the other worse. Cognitive decline is the long-horizon concern, and it is the one patients ask about most once they hear it.

Medications for Insomnia

Short-term use can help. None of these drugs are free of risk, and I’d rather say so plainly than bury it at the end of a list.

Zolpidem (Ambien) helps with both falling asleep and staying asleep, though daytime drowsiness and the odd nighttime behaviors are well documented. Zaleplon (Sonata) is shorter acting and suits the patient whose whole problem is sleep onset. Eszopiclone (Lunesta) covers onset and maintenance, and the metallic taste is a common enough complaint that I mention it before someone calls about it. Temazepam (Restoril) is a benzodiazepine, still prescribed, and carries the most dependence risk of the group.

Shortest effective course, every time. These work best as a bridge while the behavioral changes take hold, not as the plan itself.

Supplements

Melatonin is the one everybody has already tried. It earns its place in circadian problems, delayed sleep phase and jet lag especially, and sometimes in mild insomnia. One to five milligrams is the usual range, and timing matters more than dose, which is the part most people get wrong. Magnesium is worth considering in patients who are actually deficient. Leafy greens and nuts are good sources. Supplements are gentler than prescription hypnotics, and they won’t touch the underlying driver of chronic insomnia.

Sleep Hygiene

In my opinion, the most effective and lasting treatment is better sleep hygiene. Patients who hold a consistent schedule, same bedtime and same wake time seven days a week, often notice a difference within a few weeks. Cool, dark, quiet. Screens and blue light in the last hour before bed work against the transition.

Routine matters more than people expect. Reading, stretching, meditation, anything repeated nightly trains the body to wind down on cue. Caffeine, nicotine, and alcohol all interfere and are best kept well away from evening. Daylight exercise helps; a hard workout an hour before bed usually doesn’t.

One small change that pays out more than it should: turn the clock away from the bed. Patients who wake at three and check the time start doing arithmetic about how much sleep is left, and the arithmetic keeps them up longer than the original waking would have.

Keeping a Sleep Diary

When insomnia persists, a diary earns its keep. Bedtimes, wake times, awakenings, caffeine, stress, exercise. Two weeks of honest entries usually surfaces a pattern nobody had noticed, and reviewing it together tends to point at a small, specific change rather than a large vague one.

When to Seek Help

If the problem holds after the schedule and the environment have genuinely been addressed, it needs a proper evaluation. Sleep apnea, restless leg syndrome, anxiety, and depression all hide behind a complaint of insomnia. Treating the thing underneath is what fixes the sleep.

Scott Rennie, D.O.

Sources

National Institutes of Health Office of Dietary Supplements. Magnesium Fact Sheet for Health Professionals. https://ods.od.nih.gov/factsheets/Magnesium

National Sleep Foundation. How Much Sleep Do We Really Need? https://www.thensf.org

Centers for Disease Control and Prevention. Sleep and Sleep Disorders. https://www.cdc.gov/sleep

American Academy of Sleep Medicine. Clinical Practice Guideline for the Pharmacologic Treatment of Chronic Insomnia in Adults. J Clin Sleep Med. 2017;13(2):307-349.

Board Certified in Obesity Medicine and Family Medicine

This blog is for educational purposes only and does not constitute individual medical advice. Always consult your own physician before making changes to your health, medications, or treatment plan.

Hip Pain on the Side: Greater Trochanteric Bursitis Explained

On By Dr. Scott RennieIn Orthopedic/MusculoskeletalLeave a comment

Lateral hip pain that lingers and gets in the way of ordinary activity comes up constantly in my practice. One of the usual culprits is greater trochanteric bursitis, or GTB. It frustrates patients, partly because it takes a while to get named correctly. It gets called arthritis. It gets called a back problem. Catching it early changes how the whole thing goes.

The greater trochanter is the bony bump on the outside of the hip, the one you can find with your fingers. Bursae sit around it, small fluid-filled sacs that keep bone, muscle, and tendon from grinding against each other. Inflame one and you get pain along the outer hip.

Symptoms

Patients describe an ache or a burn over the side of the hip. It can run down the outside of the thigh, though it rarely travels past the knee. Activity makes it worse: stairs, long walks, and lying on that side at night, which is the complaint that finally brings people in. The area is almost always tender to pressure. Some patients mention stiffness after sitting a while, or difficulty getting the hip moving again.

The symptom picture overlaps with lumbar radiculopathy and osteoarthritis, which is exactly why it’s so often mislabeled.

Diagnosis

History does most of the work. When did it start, what makes it worse, was there a fall, and did anything change recently in activity or training. That last question earns its keep more often than people expect.

Point tenderness directly over the greater trochanter is the classic finding. A positive Trendelenburg sign, which reflects gluteal weakness, points toward associated tendon involvement rather than isolated bursitis.

Imaging isn’t always needed. X-rays rule out arthritis. Ultrasound or MRI can show bursal inflammation or gluteal tendinopathy when the case isn’t behaving.

Treatment

Most patients get better with conservative care, and I want to be clear that conservative here doesn’t mean passive. Rest from whatever’s aggravating it, ice over the outer hip, and an NSAID like ibuprofen or naproxen for pain and swelling will settle the acute phase.

Physical therapy is the piece that actually changes the trajectory. Strengthening the gluteal muscles and improving hip stability relieves current symptoms and makes recurrence less likely. I’ve had patients who could barely sleep on their side due to the pain, and after a few weeks of targeted therapy, they were back to normal activities.

When conservative care runs out of road, a corticosteroid injection into the bursa can help, and ultrasound guidance improves accuracy enough to be worth asking for. Platelet-rich plasma and shockwave therapy are still being studied in resistant cases. Surgical bursectomy is rare and belongs to the severe cases that have failed everything else.

Prevention and Long-Term Outlook

Preventing recurrence means dealing with what caused it. Weight management reduces load through the hip. Footwear matters, particularly for anyone on their feet all day on hard floors. Regular hip strengthening and flexibility work keeps the area stable, and patients who avoid long stretches of unbroken sitting or standing tend to hold their gains.

Working Together

For colleagues: keep the differential wide on lateral hip pain, and get physical therapy involved early rather than after the third failed round of anti-inflammatories. A multidisciplinary approach is what produces durable outcomes here.

For patients: this hurts, it can drag on, and it’s genuinely treatable. Most people get their mobility back and return to normal routines.

Scott Rennie, D.O.

Sources

  • Segal NA, Felson DT, Torner JC, et al. Greater trochanteric pain syndrome: epidemiology and associated factors. Arch Phys Med Rehabil. 2007;88(8):988-992.
  • Strauss EJ, Nho SJ, Kelly BT. Greater trochanteric pain syndrome. Sports Med Arthrosc Rev. 2010;18(2):113-119.
  • Bird PA, Oakley SP, Shnier R, Kirkham BW. Prospective evaluation of magnetic resonance imaging and physical examination findings in patients with greater trochanteric pain syndrome. Arthritis Rheum. 2001;44(9):2138-2145.

Board Certified in Obesity Medicine and Family Medicine

This blog is for educational purposes only and does not constitute individual medical advice. Always consult your own physician before making changes to your health, medications, or treatment plan.

Can You Do Intermittent Fasting on Ozempic or Wegovy?

On By Dr. Scott RennieIn Weight Loss & Metabolic HealthLeave a comment

Weight comes up in almost every visit I do. For some patients it is fifteen pounds standing between them and a better blood pressure number. For others it is obesity that has already done damage, and the conversation starts further back. The work can feel overwhelming from the inside. What’s changed is that the tools finally match the size of the problem. Medications like Ozempic, Wegovy, Mounjaro, and Zepbound, the GLP-1 receptor agonists, have shifted how this is approached, and paired with a structure like intermittent fasting they help people lose weight and keep it off.

What GLP-1 Agonists Do

These drugs mimic glucagon-like peptide-1, a hormone that regulates appetite and blood sugar. Given as medication, they slow gastric emptying and push stronger satiety signals to the brain, so fullness arrives earlier and stays longer. They also improve insulin sensitivity, which is why they earned their place in type 2 diabetes first.

The weight effect is substantial. Wegovy and Zepbound carry FDA approval specifically for weight loss. Ozempic and Mounjaro are approved for diabetes and produce strong weight results as well, which is the source of most of the confusion patients arrive with about which drug is which.

How They Work With Intermittent Fasting

Intermittent fasting improves insulin sensitivity, supports fat loss, and helps regulate hunger hormones. Staying with it is the hard part. Many patients tell me they can’t get past the hunger. GLP-1 medications change that equation by blunting appetite and cravings, which makes a fasting schedule something a person can actually hold.

A patient of mine started a 16:8 fasting plan (16 hours fasting, 8 hours eating) while on a GLP-1 medication. Before starting the medication, she felt shaky and irritable during fasting. After starting, she was surprised by how manageable it felt. She ate smaller meals, felt full, and didn’t struggle to maintain the fasting window.

Side Effects and Adjustments

Nausea leads the list, and it’s worst early. Diarrhea and reflux show up too. Most of it settles as the body adapts. Start low, titrate slowly, and resist the urge to chase the next dose because the scale stalled for two weeks. Patients who stay in contact through the titration get their dose adjusted before they quit over side effects, and the ones who go quiet are the ones who stop the drug entirely.

Barriers to Access

Getting these medications is its own project. Cost is the main wall. Insurance coverage for weight loss remains inconsistent in a way that’s hard to explain to a patient who has just been told the drug would help, and out-of-pocket pricing is punishing. Demand has outrun supply, so delays and shortages are part of the picture.

Then there are the compounded versions. Some pharmacies sell them well below brand pricing, and they’re not FDA-approved. Safety and potency can’t be guaranteed. I tell patients to stay away from them, and I don’t soften that advice when someone pushes back on price.

Putting It Into Context

These aren’t quick fixes. They are tools, and they work when they sit on top of durable changes: balanced eating, regular activity, attention to mental health. Intermittent fasting is one workable way to structure eating alongside them. The lifestyle piece doesn’t become optional because a medication is doing part of the lifting.

When patients pair the medication with habits they can sustain, results hold longer and vary less. The goal is a set of strategies that still works three years from now, not the fastest possible drop on the scale.

Scott Rennie, D.O.

Sources

U.S. Food and Drug Administration. FDA Approvals: Wegovy, Zepbound.

Wilding JPH, et al. Once-Weekly Semaglutide in Adults with Overweight or Obesity. N Engl J Med. 2021;384:989-1002.

Jastreboff AM, et al. Tirzepatide Once Weekly for the Treatment of Obesity. N Engl J Med. 2022;387:205-216.

American Diabetes Association. Pharmacologic Approaches to Glycemic Treatment: Standards of Medical Care in Diabetes, 2024. Diabetes Care. 2024;47(Suppl 1):S181-S202.

Board Certified in Obesity Medicine and Family Medicine

This blog is for educational purposes only and does not constitute individual medical advice. Always consult your own physician before making changes to your health, medications, or treatment plan.

Can Telemedicine Diagnose Strep Throat and Ear Infections?

On By Dr. Scott RennieIn Healthcare System & TechnologyLeave a comment

Telemedicine changed how patients reach care. It connects people quickly, saves the drive, and handles a wide range of problems well. It also has limits, and two of them show up constantly: sore throats and ear pain.

Seeing a patient virtually costs me the physical exam. With strep, looking directly at the tonsils and the back of the throat is how I separate viral pharyngitis from bacterial infection. With ear pain, I can’t see the eardrum or check for fluid behind it. Small details. They’re also the ones that decide the diagnosis.

Palpation is the other thing I lose. In clinic, I’d press along the neck for lymph node swelling, and in front of and behind the ear for tenderness. On video I can only ask the patient to describe what they feel. Sometimes they will press the area themselves and report back, which helps, and it’s not the same as an examiner’s hands.

The differential for sore throat is wide. Viral infections dominate and usually arrive with cough and congestion. Group A strep climbs the list with fever, swollen tonsils, or white patches, and no cough. Mono belongs in the picture when there is heavy fatigue and node swelling. As of 2023, COVID-19 stayed on the list whenever fever came with loss of smell. Peritonsillar abscess is uncommon and worth real attention: severe pain, trouble swallowing, a muffled voice. And not every sore throat is an infection at all. TMJ dysfunction refers pain to the throat often enough to catch people out.

Ear pain has its own list. Otitis media brings pain and sometimes fever, usually trailing a cold. Otitis externa hurts when the outer ear is touched, and there’s often a swimming history behind it. Wax occlusion produces fullness. Eustachian tube dysfunction gives pressure and muffled hearing rather than a sharp ache. Mastoiditis is rare and serious, with severe pain, swelling behind the ear, and fever. TMJ turns up here too.

Separating otitis media from otitis externa without seeing the ear is genuinely hard. Patients hand me useful clues, and pain on tugging the outer ear points toward otitis externa, but a virtual diagnosis carries far less certainty than I’d like.

Which is why in-person evaluation still matters. When symptoms are severe, persistent, or simply not adding up, an office visit allows a clinician to look directly at the throat or ear, palpate the neck, and run a rapid strep test. That’s what produces an accurate call, whether the answer turns out to be antibiotics, symptom control, or reassurance.

None of this makes telemedicine less useful. Patients who describe their symptoms carefully give me a real chance at guiding early care, and for mild or clearly viral illness a virtual visit saves an unnecessary trip. The boundaries just need saying out loud. Some problems require hands and an otoscope.

Scott Rennie, D.O.

Sources

  • Shulman ST, Bisno AL, Clegg HW, et al. Clinical practice guideline for the diagnosis and management of group A streptococcal pharyngitis: 2012 update by the Infectious Diseases Society of America. Clin Infect Dis. 2012;55(10):1279-1282.
  • Rosenfeld RM, Shin JJ, Schwartz SR, et al. Clinical practice guideline: otitis media with effusion. Otolaryngol Head Neck Surg. 2016;154(1 Suppl):S1-S41.
  • Rosenfeld RM, Schwartz SR, Cannon CR, et al. Clinical practice guideline: acute otitis externa. Otolaryngol Head Neck Surg. 2014;150(1 Suppl):S1-S24.

Board Certified in Obesity Medicine and Family Medicine

This blog is for educational purposes only and does not constitute individual medical advice. Always consult your own physician before making changes to your health, medications, or treatment plan.

Prescription bottle next to virus with red X overlay indicating medication ineffective

Why Won’t Antibiotics Cure a Viral Infection? Doctor Explains

On By Dr. Scott RennieIn Infectious DiseaseLeave a comment

Antibiotics changed the course of medicine. They save lives daily against infections that used to kill people: pneumonia, urinary tract infections, strep throat. The catch is narrow and absolute. They work on bacteria. Viruses are untouched. So an antibiotic prescribed for a cold or influenza does nothing useful, and it can still do harm.

The Risks of Misuse

Overuse drives resistance. Bacteria adapt fast, and repeated exposure teaches a population how to survive the drug that used to clear it. Those are the organisms we call superbugs. They make ordinary infections harder to treat, and healthy patients aren’t exempt from that. In its 2019 threats report, the CDC counted more than 2.8 million antibiotic-resistant infections a year in the United States and over 35,000 deaths.

Side effects are the nearer problem for most patients. Antibiotics disturb the gut microbiome, and nausea, diarrhea, and abdominal pain follow. Sometimes that disruption opens the door for Clostridioides difficile and a severe colitis.

Yeast overgrowth is common too. Clear out the normal bacterial balance and Candida fills the space, showing up as oral thrush or a vaginal yeast infection. I’ve had patients relieved that their original infection improved, only to be frustrated by new symptoms a week later.

Using Antibiotics Wisely

The goal is correct use, not avoidance. That’s what antibiotic stewardship means in practice.

Step one is deciding whether the infection is even bacterial. A sore throat is usually viral pharyngitis. Fever with swollen tonsils and no cough moves strep up the list, and a rapid strep test settles it rather than leaving it to impression. Ear pain needs a careful look to separate a viral picture from bacterial otitis media.

Prevention cuts the need in the first place. Vaccination, hand hygiene, safe food handling. I keep telling patients that washing hands before eating and after being out in public does more to keep them off antibiotics than anything I prescribe.

When antibiotics are the right answer, they’ve got to be taken as directed. Stopping early, skipping doses, and saving leftovers all undermine the course and feed resistance. Sharing a prescription with a family member is its own category of mistake.

Where This Leaves Us

Antibiotics remain among the most powerful tools in medicine, and they aren’t free. Misuse buys resistant bacteria, gastrointestinal misery, and yeast overgrowth. Careful prescribing, honest patient education, and prevention are what keep these drugs working for the people who will need them next.

Scott Rennie, D.O.

Sources

Board Certified in Obesity Medicine and Family Medicine

This blog is for educational purposes only and does not constitute individual medical advice. Always consult your own physician before making changes to your health, medications, or treatment plan.

Wall clock with illustrations of various foods representing mealtime hours

Does Intermittent Fasting Work? A Doctor Explains

On By Dr. Scott RennieIn Weight Loss & Metabolic HealthLeave a comment
snake-diet-fasting

Intermittent fasting, sometimes called therapeutic fasting or intermittent energy restriction, has gained attention both in the media and in clinical practice. Patients ask about it regularly, often because they’ve heard it can help with weight loss or with lowering blood sugar in diabetes.

I have no ties to pharmaceutical companies or research groups, and I don’t profit from sharing this information. My purpose is simply to explain what I’ve seen and what the research shows. For patients with diabetes or heart disease, or those taking medications, I always recommend making changes under the guidance of a physician. Fasting can alter medication needs quickly, sometimes within days.

Why Weight Matters

About 75% of adults in the United States are overweight or obese, and the number continues to rise. Excess weight contributes to metabolic syndrome, diabetes, hypertension, and heart disease, and it increases the risk of stroke and some cancers. Many patients struggle with arthritis or back pain from the mechanical stress of extra weight. Others develop sleep apnea, fatigue, or sexual dysfunction. Beyond the health issues, there are real-world effects: trouble traveling, difficulty exercising, and limits on daily activities.

Why “Eat Less, Move More” Falls Short

The common advice is to cut calories and exercise more. Most patients I’ve seen have tried this approach at some point. The problem is that it rarely works long term; weight usually returns, often within months.

A striking example came from contestants on The Biggest Loser. Many lost large amounts of weight during the show, but most regained it later. As one participant admitted, “we’re all fat again.” Research supports this. A 2012 study in the New England Journal of Medicine followed patients on calorie restriction and found no sustained improvement in BMI after five years. The Women’s Health Initiative produced similar results over nine years.

The reason is physiology. When calorie intake drops, the body adapts by slowing its metabolism. If someone weighs 230 pounds and cuts back to 1500 calories a day, the body may drop its resting burn rate to 1300 calories. That person feels cold, sluggish, and hungry. Hormones like ghrelin keep signaling hunger, even long after dieting begins, and eventually weight creeps back.

The Role of Insulin

Energy comes from two sources: food and stored fat. When we eat, insulin rises and directs the body to store extra energy as glycogen or fat. At the same time, fat breakdown is switched off. This makes weight loss difficult if insulin stays high, especially with frequent meals or a high-carbohydrate diet.

How Intermittent Fasting Works

Intermittent fasting lowers insulin levels by reducing the frequency of eating. With food energy unavailable, the body taps into fat stores. Fasting can be combined with any diet, but it works particularly well with lower carbohydrate intake, since that also keeps insulin levels down.

Patients use different fasting schedules. A common one is the 16:8 approach, where meals are limited to an 8-hour window. Some prefer one meal a day. Others follow alternate-day fasting or the 5:2 pattern, eating normally for five days and restricting calories for two.

Water intake is essential. During fasting, the body needs extra water to help mobilize fat for energy. Electrolytes, especially sodium, potassium, magnesium, and calcium, also need attention, since ketosis increases their loss through the kidneys. Many patients avoid “keto flu” symptoms like dizziness, fatigue, or cramps by adding broth or electrolyte-rich foods.

What the Evidence Shows

Fasting does not slow metabolism. In fact, studies have shown a slight increase in metabolic rate during fasting, partly due to rises in norepinephrine (Zauner C, Am J Clin Nutr 2000;71:1511-1515). Hunger doesn’t keep building either. Ghrelin levels rise and fall around usual mealtimes, then settle back if food is skipped.

Research also shows fasting preferentially burns fat rather than muscle (Drenick EJ, Am J Public Health Nations Health. 1968;58(3):477-484). Men and women both respond with fat loss, averaging about half a pound per fasting day in controlled studies.

Beyond weight, there are possible additional benefits. Animal studies suggest longer lifespan, reduced cancer risk, and protection against neurodegenerative conditions. Human research is still developing, but some studies show improved insulin sensitivity, better blood sugar control, and even improved mood and cognition.

Safety and Practical Considerations

Fasting is not new. Hippocrates wrote about it, Plato praised it, and major religions have incorporated fasting traditions for centuries, from Ramadan to Lent to the Jewish high holy days. In most overweight patients it is safe when supervised. It is not appropriate for those who are pregnant, underweight, or struggling with eating disorders.

Patients with diabetes, especially those on insulin, need careful monitoring. Many see rapid improvements in blood sugar and may require lower doses. Some patients with type 1 diabetes using low-carb diets report more stable glucose and lower A1c.

For patients who like numbers, tools exist to track progress. Ketone meters can show if the body is burning fat. Blood sugar meters can help patients see how specific foods affect them. Insulin testing is available in labs, but not over the counter.

The Bottom Line

Intermittent fasting is not a fad. It is a structured way to reduce insulin, tap into fat stores, and improve metabolic health. Like any medical intervention, it should be individualized. With guidance, many patients find fasting more sustainable than calorie restriction and more effective for long-term weight control.

Scott Rennie, D.O.

Sources

  • Zauner C, et al. Resting energy expenditure in short-term starvation is increased as a result of an increase in serum norepinephrine. Am J Clin Nutr. 2000;71:1511-1515.
  • Drenick EJ, et al. Prolonged starvation as treatment for obesity. Am J Public Health Nations Health. 1968;58(3):477-484.
  • Sumithran P, et al. Long-term persistence of hormonal adaptations to weight loss. N Engl J Med. 2011;365:1597-1604.
  • Look AHEAD Research Group. Long-term effects of a lifestyle intervention on weight and cardiovascular risk factors. N Engl J Med. 2013;369:145-154.

Board Certified in Obesity Medicine and Family Medicine

This blog is for educational purposes only and does not constitute individual medical advice. Always consult your own physician before making changes to your health, medications, or treatment plan.