If you find yourself feeling under the weather with a fever, body aches, and other symptoms, you may wonder what is making you feel so bad. Is it seasonal influenza (commonly called the flu)? Or could you have COVID-19? While the two illnesses share many similarities, there are a few differences.
Path to improved health
COVID-19 and the flu are both caused by viruses. But they are caused by different viruses. COVID-19 is caused by a coronavirus. These viruses have been around for a long time. In fact, certain coronaviruses can cause you to get the common cold, but there is a new coronavirus called SARS-CoV-2. That is what causes COVID-19. Flu, on the other hand, is caused by the influenza virus. This is a seasonal virus with two types: Influenza A and Influenza B.
You also can catch COVID-19 and the flu in similar ways. When a person talks, sneezes, or coughs, tiny, invisible particles leave their mouth and nose and travel through the air. These particles are where the virus can live. If you breathe in these particles, the virus is then inside your body and can make you sick. Also, if you get the particles on your hands and then touch your mouth, nose, or eyes, you can get sick. Therefore it’s so important to wash your hands frequently.
COVID-19 is much more contagious than the flu. That means it more quickly and easily passes from one person to another.
People most at risk
While anyone can get COVID-19 and the flu, some groups of people are at a higher risk of getting sick. For COVID-19, seniors, people who are pregnant, people with lung disease, heart disease, or diabetes have a greater risk.
People with asthma, diabetes, or heart disease are at a greater risk of getting the flu. Children, people who are pregnant, and adults older than 65 years old are also at increased risk for the flu.
Both COVID-19 and the flu have many of the same symptoms, including:
- Trouble breathing
- Extreme tiredness
- Sore throat
- Stuffy nose
- Body aches, including headache
If you have COVID-19, you may also lose your sense of smell or taste.
If you have any of these symptoms, contact us right away. We can diagnose which illness you have and what you should do next.
How long are you sick?
It is possible to spread COVID-19 and the flu to others before you even know you are sick. If you have COVID-19, you can spread the virus 2 days before you have symptoms. After symptoms begin, you are likely contagious for 10 days. It is important to stay away from other people during this time to keep them from getting sick. If you are around someone who has COVID-19, it can take between 2 and 14 days for you to develop symptoms.
With the flu, you can spread it 1 day before your symptoms begin. Once you have symptoms, you are contagious for up to 7 days. This time can be longer for kids and seniors. If you are exposed to someone with the flu, it can take between 1 and 4 days for you to develop symptoms.
People are usually sicker for a longer period with COVID-19 than with the flu.
There are different tests that can confirm if you have COVID-19. Some tests require a long cotton swab to be put in your nose. The end of the swab collects a sample from your nasal cavity because this is where the germs live. The swab is then sent to a laboratory for testing. The other type of test for COVID-19 requires a blood sample. Your blood is then sent to a lab for testing.
If we feel you have the flu, we can perform one of two tests. One test involves putting a swab up your nose. This swab will be tested in-house for immediate results. The other test involves collecting a sample from the back of your throat. It will be sent to an outside lab for testing.
Doctors are constantly learning about COVID-19 and are investigating several treatment options to treat the infection and the complications associated with the infection. Many companies are in various stages of developing vaccines to prevent COVID-19 infection.
There is a vaccine you can get to help protect you against the flu. It is given in the form of a shot in your arm. We generally recommend everyone older than 6 months old get the yearly flu shot. If you get the flu, there are medicines we can prescribe to help you relieve symptoms.
Note: The flu shot does not give you the flu.
If you have had COVID-19, it will likely take you a long time to recover. It may be weeks before you feel like yourself again.
People who have had the flu usually feel much better about 2 weeks after getting sick.
Things to consider
COVID-19 and the flu share many complications. These include pneumonia, respiratory failure, kidney failure, and blood infections. These illnesses can also make existing conditions—including issues with the heart, lungs, and diabetes—worse. In severe cases, both illnesses may lead to death.
If you have COVID-19, you may also develop blood clots in your legs, lungs, heart, or brain. Your chances for these side effects go up if you have heart disease, lung disease, or diabetes. Some children develop multisystem inflammatory syndrome. This is a serious condition, but it is not very common.
If you have had the flu, you may develop a sinus infection or an ear infection. You may also get pneumonia, which can be serious. Severe side effects are more common in people who are younger than 5 years old or older than 65 years old, pregnant, or who have asthma, diabetes, or heart disease.
- Centers for Disease Control and Prevention: Coronavirus Self-Checker
- Last Updated October 2020 | This article was created by familydoctor.org editorial staff and reviewed by Robert “Chuck” Rich, Jr., MD, FAAFP