Skip to main content

Does a fever mean the flu, COVID-19 or pneumonia?

Updated: June 16, 2025 | 7 minutes to read

Written by: Barbara Brody

A person reads a thermometer while lying under blankets on a couch with tissues nearby.

Almost everyone has experienced the cruddy symptoms of a fever, cough and aching body. In pre-pandemic times, the first culprit to come to mind might have been the flu. But COVID-19 has entered the chat, and this condition has similar symptoms. If the cough is particularly bad, a provider might also look into a diagnosis of pneumonia, which is an infection of the lungs. 

Anyone with these symptoms is encouraged to speak with their health care provider and get an immediate test for COVID-19.1 It’s also a good idea to read up about what might be wrong and the treatments a provider might recommend for these different conditions.

In this article:

Symptoms of the flu

What does the flu look like?

The flu is caused by a virus (influenza) and often causes these symptoms:2

  • Chills
  • Cough
  • Fatigue3
  • Fever
  • Muscle aches

Another possible symptom is a runny or stuffy nose. Many of these symptoms are also common with COVID-19, but with the flu, they can come on suddenly.4

It’s important to talk to a medical provider if these symptoms pop up, especially if a home COVID-19 test turns out negative. The provider might diagnose someone with the flu based on symptoms alone5 or recommend a flu test, says Shannon Neale, MD, a family physician with HealthPartners Park Nicollet in St. Louis Park, Minnesota.6

Are there prescription treatments for the flu?

Some people are at higher risk for serious illness from the flu because of an underlying health condition, such as asthma, diabetes or heart disease. In those cases, a provider may decide to prescribe an antiviral medication.7 “Other people who may need an antiviral medication because they are at high risk for complications from influenza include pregnant women, very young children (especially under the age of 2) and people who live in nursing homes or other long-term care facilities,” says Dr. Neale.8

Are there over-the-counter (OTC) flu products to consider?

Most people with the flu should get plenty of rest and stay hydrated. OTC medications can also help reduce symptoms. Ibuprofen or acetaminophen can help bring down a fever and ease aches and pains.9 For chest congestion, an expectorant like Mucinex (guaifenesin) may help loosen things up.10, 11 Always check with a health care provider before taking any OTC medications.

How long does the flu last?

Flu symptoms usually last five to seven days. Antiviral medication or a flu shot can help to reduce the duration of symptoms.12

Need a flu shot? They’re available from late summer to early spring at MinuteClinic® and most pharmacies.

Symptoms of COVID-19

What does COVID-19 look like?

For the past few years, “It’s COVID-19 unless proven otherwise,” says Dr. Neale. Symptoms of COVID-19 include:13

  • Body aches
  • Cough
  • Fever
  • Unusual fatigue

With COVID-19, people are also known to lose their sense of taste or smell. Not everyone with COVID-19 has this problem, but it’s uncommon with the flu.14 So that’s one difference between the two infections.

If COVID-19 is a possibility, the Centers for Disease Control and Prevention (CDC) currently recommends testing if a person has risk factors for severe illness.15 If a home test is negative, follow current CDC guidelines on retesting.16 It may be recommended to use a total of two to three tests depending on whether there are symptoms. For a positive result, schedule a visit with a primary care or MinuteClinic provider.

For products to help with at-home testing, consider a CVS Health® at-home COVID-19 test kit, the Flowflex COVID-19 antigen home test or the BinaxNOW COVID-19 antigen self-test.

Are there prescription treatments for COVID-19?

Most people with COVID-19 don’t need a prescription, but oral antiviral treatment options are available to treat mild to moderate COVID-19 in people who are more likely to get very sick. This can include adults age 65 or older as well as people who are unvaccinated, are not up-to-date on their COVID-19 vaccinations, have certain medical conditions (like chronic lung or heart disease) or have a weakened immune system. A health care provider might prescribe an antiviral medication to treat the infection.17

Are there OTC COVID-19 products to consider?

As with the flu, recovering from COVID-19 requires resting up and staying hydrated. For a fever or body aches, ibuprofen or acetaminophen can help. Mucinex (guaifenesin) or Robitussin may help with cough and congestion.18 Always speak with a health care provider before starting or stopping any OTC medications or supplements.

How long does COVID-19 last?

The symptoms from COVID-19 can last anywhere from a few days to several weeks, says Dr. Neale. Current guidelines recommend staying home and away from others until symptoms are improving and there isn’t a fever for at least 24 hours without using any fever-reducing medication. It’s recommended to take extra precautions for five days after resuming normal activities, such as using proper hygiene methods, masks and physical distancing.19

Symptoms of pneumonia

What does pneumonia look like?

Pneumonia means that the air sacs in the lungs have become infected and inflamed. These sacs may fill with fluid or pus, which may lead to coughing up phlegm and difficulty breathing.20 A doctor may order a chest X-ray to see whether the sacs are filled with fluid instead of air.21

Pneumonia can be caused by the flu, COVID-19 or many other infectious agents, including other viruses, bacteria or fungi. Viral pneumonia can follow a cold or flu that persists.22 Bacterial pneumonia is caused by bacteria and may be accompanied by a mucus-y cough, high fever and severe chest pains.23 “If you have trouble breathing, get medical attention right away,”24 says Andrew Bryant, MD, associate professor at the University of Florida College of Medicine.

Are there prescription treatments for pneumonia?

Many people with pneumonia need antibiotics, says Dr. Bryant. (Even if an infection had a viral origin, such as COVID-19, a bacterial infection may have set in.25) Providers might call for a blood test to help determine whether pneumonia is viral or bacterial, since antibiotics kill only bacteria.26

Are there OTC pneumonia products to consider?

It’s important to speak with a provider for guidance around OTC products. Ibuprofen or acetaminophen can help reduce a fever. Cough medicine is a little trickier, because coughing can help the body loosen and remove fluid from the lungs, and taking a cough suppressant could backfire by slowing this process down.27

Vaccines for flu, COVID-19 and pneumonia28

It’s important to stay up to date on vaccinations against the flu and COVID-19.29 It’s also important to stay current with pneumococcal pneumonia vaccinations for people over 50 and for adults who are ages 19 through 49 with certain medical risks or conditions.30 The pneumococcal pneumonia vaccine helps protect against Streptococcus pneumoniae bacteria, which is the most common cause of bacterial pneumonia.31

Vaccines for all three of these conditions can be administered by a health care provider or at a local MinuteClinic location.

This content is for informational purposes only and is not medical advice. Consult your health care provider before taking any vitamins or supplements and prior to beginning or changing any health care practices.

You may also like

Explore more topics

Browse all topics