If you have sniffles, sneezes, coughing or sore throat, it can be hard to tell if your symptoms are from allergies, a cold, the flu, COVID-19 or RSV.

Until you know for sure what’s causing your symptoms, it’s always good to err on the side of safety and stay home and away from others.

So how can you tell what you have?

Stay Alert for COVID-19

The symptoms for COVID-19 and the flu are similar. You likely won't be able to tell the difference from symptoms alone. 

The signs of COVID-19   include fever, cough, shortness of breath, sore throat, nausea or vomiting, and diarrhea, says the Centers for Disease Control and Prevention (CDC).  You may also have other symptoms that you can get when you have a cold or the flu, such as feeling tired, muscle or body aches, or headaches.

If you suspect you have COVID-19, take a test to be sure. Learn about your options for testing.  If you test positive, follow CDC guidelines for what to do  when you get a respiratory virus.

If your symptoms are mild, you may get better on your own. But it is still important that you not go around others until you're well. If you have more serious symptoms, like a fever or trouble breathing, call your doctor right away. 

The CDC recommends that everyone 6 months old and older should get an updated COVID-19 vaccine.  

RSV

RSV is a common respiratory virus that infects the lungs, but it can also affect the nose and throat. The CDC says RSV spreads in the fall and winter along with other respiratory viruses, like flu and COVID-19. It usually peaks in December and January.

RSV usually causes mild, cold-like symptoms. But it can be more serious for infants and older adults. For them, it can be dangerous and may require a hospital stay. The CDC recommends vaccinations for infants, some young children and older adults.

Colds and Allergies

When you don’t feel well, you might wonder whether it’s a cold or allergies. They share some similar symptoms like coughing, sneezing, and runny or stuffy nose. So how can you tell the difference?

How long your problems last is one of the big clues. Colds don’t often stick around more than two weeks. Allergy symptoms can linger much longer.

Colds are caused when a virus gets into your body and makes you sick. Your immune system launches a defense against germs. Your body fighting off the cold is what causes symptoms like a stuffy nose or cough. Unlike allergies, colds can also make your body ache.

Allergies are caused by an overactive immune system. Your body overreacts to harmless things like pollen or dust and works to protect you from them. That can cause coughing, sneezing and stuffy nose, like colds. Unlike colds, allergies often cause watery, itchy eyes.

Also keep in mind that colds are contagious, while allergies are not. WebMD offers a full list of similarities and differences. 

Flu

While flu shares some symptoms with colds or allergies, it is more severe and causes more serious symptoms. It also tends to come on much quicker and more severely. The American Lung Association says to watch for these signs of flu:

• Sudden, high fever
• Headache, muscle and joint aches and pain
• Dry cough
• Sore throat
• Chills
• Nasal congestion
• Runny nose
• Fatigue
• Stomach symptoms like nausea, vomiting or diarrhea (more common in children)

Get Your Flu Shot

Like colds, flu is contagious and is caused by a virus. Unlike colds, you can get a vaccination to help protect yourself and others from flu.

The CDC says most people who are six months or older should get a yearly flu shot. It takes about two weeks after vaccination for the shot to protect against flu virus infection. So don’t wait until peak flu season to get your shot. Get it as soon as it is available. Your health plan may cover a flu shot at no cost* to you when you go to your primary care doctor or use an in-network provider.

Avoid Germs

To stay healthy, protect yourself from germs of all kinds:

• Wash your hands often with soap and water for at least 20 seconds.
• Use hand sanitizer often throughout the day.
• Try not to touch surfaces used by a lot of people, like door handles, light switches, phones, keyboards and flat surfaces. Disinfect those surfaces around your home or office often.
• Keep your hands away from your eyes, nose, and mouth, especially when you’re away from home.
• When you’re out in public, try to stay 6 to 10 feet away from other people.

*Preventive services at no cost applies only to members enrolled in non-grandfathered health plans. You may have to pay all or part of the cost of preventive care if your health plan is grandfathered. To find out if your plan is grandfathered or non-grandfathered, call the customer service number on your member ID card.

Sources: Symptoms of COVID-19,  Centers for Disease Control and Prevention, 2024; Who Needs a Flu Vaccine,  CDC, 2024; Is it a Common Cold or Allergies,  WedMD, 2023; Flu Symptoms and Risk Factors,  American Lung Association, 2023; Runny Nose,  Cleveland Clinic, 2023; About RSV,  CDC, 2024

Originally published 9/2/2021; Revised 2022, 2023, 2024