How to Tell the Difference between Flu, RSV, COVID-19, and the Common Cold

COVID-19, influenza (flu), and respiratory syncytial (sin-SISH-uhl) virus (RSV) can cause many of the same symptoms, including a fever, stuffy or runny nose, coughing, and sneezing. To help you tell the difference, the National Foundation for Infectious Diseases (NFID) developed a simple chart, available in English and Spanish.

While these viruses usually don’t cause serious illness, some people are more likely than others to get very sick or even die. It’s important to know what virus you have because there are specific treatments that may help you recover faster and avoid serious complications.

Who is Most at Risk?

The people most likely to get very sick from respiratory viruses include:

• Pregnant women
• Infants and young children
• Older adults
• People who have another health problem including:
  • Asthma
  • Diabetes
  • Chronic heart, kidney, or lung disease
  • A weakened immune system from HIV, cancer, or organ transplantation

Why Testing Matters

Because these diseases have many of the same symptoms, it’s important to get tested to figure out what is making someone sick.

Drugs are available that can make COVID-19 or flu less severe, but they work best when taken within a few days of the start of symptoms. Getting tested quickly gives the patient the best chance for treatment.

Signs of Trouble

Most symptoms can be handled at home, but people with any of these symptoms should get emergency medical help immediately:

• Trouble breathing
• Bluish skin
• Chest pain
• Confusion
• Trouble waking up or staying awake

Treatment Options

Antiviral drugs are available to treat flu and COVID-19.

COVID-19: If you are in one of the groups of people who are likely to get very sick from COVID-19, contact a healthcare professional as soon as possible if you test positive. Prescription drugs for COVID-19 work best if taken in the first 5-7 days of symptoms. If you are not at risk for serious illness, you can manage your symptoms with over-the-counter medicines.

Flu: People at risk of getting very sick may get a prescription for an antiviral drug that can prevent the worst effects of flu. For people who are not likely to get seriously ill, the drugs can take a day or two off the time they have symptoms. They work best if taken in the first 2 days of the illness.

RSV: There is no treatment for RSV, but over-the-counter medicines can manage mild symptoms. (Never give children aspirin.) People who get very sick may need to go to the hospital. RSV can be very serious for young children and older adults.

Prevention

Immunization is the best way to protect against all three diseases. Healthcare professionals recommend RSV vaccines or monoclonal antibodies for very young children, pregnant people, and older adults. They recommend updated COVID-19 vaccines and annual flu vaccines for nearly everyone in order to keep up with the changing virus.

Getting vaccinated doesn’t guarantee you won’t get sick. But vaccination lowers the odds that you will get seriously ill or die. And people who get a COVID-19 vaccine are less likely to develop Long COVID.

Who should get vaccinated against:

COVID-19 (updated vaccine):

• Adults age 50 years and older
• Children age 6-23 months
• Children and adults who have chronic health conditions
• Older children who have or live with someone who has a chronic health condition
• Women who are pregnant or breastfeeding
• Residents of long-term care facilities
• Adults and children with impaired immune systems due to disease (e.g., cancer or HIV) or medications they must take to treat a health condition (e.g., for organ transplantation)
• Household members and those in close contact with individuals who are immunocompromised
• Anyone age 6 months and older who wants to be vaccinated against COVID-19

Flu (annual vaccine):

• All children 6 months old or older
• All pregnant people
• All adults

An RSV vaccine (single, lifetime dose) is recommended for:

• Pregnant women between 32-36 weeks of pregnancy during September-January
• All adults age 75 years and older
• Adults age 50–74 years who:
  • Have certain chronic health conditions, such as lung disease, heart disease, or weakened immune systems
  • Live in nursing homes

An RSV monoclonal antibody shot is recommended for:

• Infants younger than 8 months, if the mother didn’t get vaccinated
• Young children 8-19 months old with lung conditions or weakened immune systems

 

Reviewed and updated April 2026

Sources: American Academy of Pediatrics, American Academy of Family Physicians, American College of Emergency Physicians, Infectious Diseases Society of America