01/09/2026
Common Respiratory Virus Symptoms
Symptoms of colds, influenza, COVID-19, and RSV have a lot of overlap.
Common symptoms of respiratory illnesses include:
Change in taste or smell (more common with COVID-19).
Cough.
Fatigue.
Fevers or chills.
Headaches.
Loss of appetite.
Muscle/body ache.
Runny nose.
Shortness of breath/difficulty breathing.
Sneezing.
Sore throat.
Wheezing.
The symptom overlap makes it difficult to know which illness you have purely from your symptoms, Dr. Snyder says.
“You can’t distinguish the respiratory viruses based on your symptoms,” he says. “A rhinovirus causes what we call rhinosinusitis, which is sinus congestion. Could that be COVID? Yes. Is the flu always going to present with fever, achiness, and maybe a dry cough? Often, but not always.
“So, the viruses, while on average, they have some distinct characteristics on an individual level, you can’t tell what you’ve got (based on symptoms).”
Some symptoms may present differently in children. Learn how to protect children from respiratory viruses like the flu, COVID-19, and RSV.
Often, testing is the only way to diagnose which respiratory illness you have.
Testing for Respiratory Viruses
If you’re experiencing symptoms of a respiratory virus, getting tested is especially important. This is especially the case if you’re at risk for a severe illness or care for people who are at higher risk. The flu and COVID-19 cause severe illness, hospitalizations, and deaths more often than other respiratory illnesses.
Over-the-counter antigen tests are available for the flu and COVID-19. You can also discuss with your doctor the possibility of undergoing laboratory tests.
It’s best to get tested for the flu and COVID-19 as soon as you start experiencing symptoms. Antiviral medications for both illnesses are most effective when they’re given early in the disease course.
“I would suggest, within the first couple of days of knowing that you’re sick, to get a test,” Dr. Snyder says. “You can talk to your doctor about a (lab) test or a home antigen test. The antivirals are most effective if given in the first couple of days. You really need to give it in the first two to three days for their maximum effect.”
Respiratory Virus Treatment
If you test positive for the flu or COVID-19, talk to your doctor about getting a prescription for an antiviral treatment. Antivirals can reduce your risk for severe complications.
They’re especially important for people who face a higher risk of complications, including:
Children (for the flu).
Older adults.
People with compromised immune systems.
People with existing medical conditions.
Pregnant people.
In addition to antivirals, you can also take steps to manage your symptoms. This can include taking over-the-counter medications, resting, and staying home if you’re sick.
What Should I Do if I’m Feeling Sick?
If you have symptoms of a respiratory illness, here’s what you can do:
Stay home — Don’t go to work or school until your symptoms subside to avoid spreading respiratory viruses to others. “You should definitely stay home while you have a fever because that’s the most contagious period for these viruses, and within 24 hours of your fever going away,” Dr. Snyder says.
Wear a mask — If you’re out in public, wearing a mask that covers your nose and mouth can reduce your risk of spreading a respiratory virus to others.
Get tested — Take at-home flu and COVID-19 tests, or talk to your doctor about getting an in-office test.
Get treatments — If you test positive for flu or COVID-19, ask your doctor about antiviral treatments. You can also try over-the-counter medicines or home remedies to manage your symptoms.