Person checking their temperature

Due to the emergence of the “tripledemic” - the collision of the flu, respiratory syncytial virus (RSV) and COVID-19 — has made it difficult to identify which illness you may have.

But if they strike, how can you tell the difference?

“They all look the same—until they don’t,” says Dr. Eli Coria, DO, family physician with Memorial Hermann Medical Group (MHMG) Firethorne “You can’t assume it’s one and not the other. It’s important to test early because we can start antivirals.”

The trio can spread via sneezing and coughing, which disperse droplets in the air. Getting enough sleep, taking it easy and drinking plenty of fluids can help you feel better faster.

But before you take to your bed, alert your primary care physician. Antivirals could aid your recovery further—and the sooner you act, the better.

In the meantime, Dr. Coria helps you distinguish between the threatening threesome.


Symptoms: Cough, congestion and stuffy nose are early signs. Runny nose, post-nasal drip or sore throat can be accessories to the crime of viral infection.

Rx: “As with the other viruses, the primary treatment is plenty of rest, sleep and staying hydrated,” Dr. Coria says. Over-the-counter cold/flu cough suppressants can help—but don’t give them to children under age 6. If caught early, your doctor may prescribe antiviral meds.

Tests: Hospitals usually reserve RSV tests for pediatric emergency centers and hospitals, not clinics.

Most vulnerable: People of all ages can catch RSV, but children ages 4 and under are more likely to suffer significantly, have trouble breathing or need to be hospitalized to get breathing assistance.

Be concerned: Since children may not be able to communicate their distress verbally, watch for signs that they’re working increasingly hard to breathe. When they try to inhale, there may be visual sucking in beneath their rib cage, and greater pushing and retracting their belly, Dr. Coria says. “That’s a definite sign to head to the ER, because they may need supplemental oxygen or other supportive care.”

Timing: Congestion and other signs arise within a week of exposure.

Most contagious: You can unintentionally share this bug for up to two weeks.

Duration: Symptoms peak between days 7-10.

Season: Winter is prime time for RSV. “We’re hunkered down at home, get together in big groups for the holidays and travel by air.”

Don’t bother: Unless your doctor says otherwise, antibiotics won’t help. They fight bacteria, not viruses.


Symptoms: Cough, sore throat, runny and stuffy noses are early signs, as with the other viruses. But flu often compounds the misery with fever and body aches. Nausea, vomiting and diarrhea also may occur. Unlike RSV and COVID-19, “patients can tell me exactly when they fell ill,” Dr. Coria says. “They say they feel like they’ve been hit by a truck.”

Rx: Over-the-counter meds can relieve some symptoms, as can prescribed antivirals such as Tamiflu®. The earlier you take antivirals the better, ideally within the first 48 hours of symptoms. “You’re trying to head off the virus right at the start and stop the vulnerable from ending up in the hospital,” he says. They work by thwarting viruses from replicating, and thus can cut the length and severity of a virus. Yet you may feel worse the first few days after you first begin taking antivirals. “As the virus dies off, you get a heightened immune response and more body aches and fever.” But the payoff is worth the pain.

Tests: Your doctor can do a nasal swab test, similar to tests performed for RSV and COVID-19. Results can be available within 15 minutes.

Most vulnerable: The elderly, very young and those with asthma or chronic respiratory disease may be at greater risk.

Be concerned: Head to the ER if you or your family member struggles to breathe or has severe chest pain.

Timing: You should get tested when you have symptoms, which tend to occur within a week of exposure. “If you have no symptoms, there may not be enough virus to show up on tests,” Dr. Coria says.

Most contagious: As with RSV, you’re most likely to spread the disease the first 7-10 days after getting it.

Duration: Usually the flu lasts up to two weeks, much like RSV.

Season: Historically, flu attacks between October and February, he says. “But the last two years have been different for the entire world. Last year, flu went a lot longer than expected, into March and April.”

Do bother: “The annual flu vaccine is highly recommended,” Dr. Coria says. Each year’s shots are targeted to the current strains. “While it doesn’t guarantee to prevent infection, it lowers your potential of contracting the flu—and can reduce its severity,” he says. “The more people who are vaccinated, the lesser the likelihood of the flu spreading to begin with.”


Symptoms: Signs of illness may vary but tend to include upper respiratory distress such as runny nose, congestion, sore throat, cough, headache, fatigue and body aches. You also might experience abdominal symptoms such as nausea, diarrhea and vomiting. “But you could have just one symptom and test positive for COVID-19,” Dr. Coria says. “Past variants led to complete loss of taste and smell, but less so with omicron.”

Rx: You need plenty of water and sleep and can take OTC meds that target symptoms, he says. Your doctor may prescribe an antiviral, such as Paxlovid™ and Lagevrio™ (molnupiravir). They’re most effective when taken within five days of the onset of symptoms.

Tests/Timing: “With COVID-19, it’s important to test at home, because we can start antivirals,” he says. “Home tests are widely available.” You may get a false negative if there’s not enough virus in your nasal passages, so you should test again two to three days later if symptoms continue or worsen.

Most vulnerable: The most likely to be hospitalized or risk death are those who are unvaccinated or are immunocompromised, such as those with cancer or who are taking treatments that suppress immunity. People over 65 and under 12 months also are at greater risk. “But the COVID-19 infection can be far more severe for anyone than the other viruses,” Dr. Coria says. “Even young people are being hospitalized or dying.”

Be concerned: If you struggle to breathe or have severe pain, head to the ER.

Most contagious: You’re most likely to spread COVID-19 in the first 10 days, which is why self-quarantine is recommended.

Duration: Generally, COVID-19 peaks within 7-10 days. If your symptoms don’t improve within two weeks, you should alert your doctor.

Season: “We’re seeing waves throughout the year,” Dr. Coria says. “COVID-19 tends to spike after holidays and through the winter, but it can happen any time of year.”

Do bother: Get vaccinated. “Everyone should take COVID-19 seriously, and the potential risks of a COVID-19 infection outweigh the side effects of vaccination for most people,” he says. “The risks of COVID-19 include long COVID (with lingering exhaustion, breathing difficulties and other signs), hospitalization and teetering on the edge of developing diabetes, heart disease and coronary artery disease—all life-altering diseases.” If you haven’t been vaccinated since September, Dr. Coria recommends getting a COVID-19 booster, which now targets omicron, currently the most dominant of strains.

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