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COVID-19 (coronavirus disease): Symptoms and treatment

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Symptoms of COVID-19

Symptoms may start 1 to 14 days after exposure to the virus, but typically appear within about 2 to 4 days. People who are vaccinated can still become infected with or without symptoms.

Symptoms of COVID-19 can vary:

You may be infected but not have symptoms. However, you can still spread the virus to others, including if you:

Common symptoms

Some of the more commonly reported symptoms include:

Severe symptoms

Severe symptoms of COVID-19 include:

Call 9-1-1 or your local emergency number if you develop severe symptoms.

Re-infection

An individual who has been previously infected or vaccinated can become re-infected. This is because their immune response decreases over time and the virus continues to evolve. Keeping up to date with COVID-19 vaccination helps to protect from re-infection and will prevent severe illness if infection does occur.

Complications of COVID-19

Complications of COVID-19 can include:

Multisystem inflammatory syndrome is a rare complication that has been documented among children (MIS-C) and adults (MIS-A). This is when inflammation (or swelling) affects multiple organs. It can occur 2 to 6 weeks after a COVID-19 infection.

Long-term complications

Some people who become infected with COVID-19 may experience long-term symptoms, even after they recover from their initial infection. This has been called post COVID-19 condition or long COVID.

Studies are underway to further understand what causes post COVID-19 condition and how to diagnose and treat it.

If you think you have this condition, talk to your health care provider about how to manage your symptoms.

Learn more:

If you become ill

If you have symptoms of COVID-19 stay, at home and limit close contact with others. It's especially important to limit contact with people who are at risk of complications from COVID-19 infection.

You can also use personal protective measures to help reduce the risk of spreading infection to others. For example, wearing a well-fitting respirator or mask and improving indoor ventilation.

If you require an in-person appointment, tell your health care provider about your symptoms over the phone and follow their instructions.

If you need immediate medical attention, call 9-1-1 and tell them your symptoms.

Learn more:

Diagnosing COVID-19

Your health care provider may suspect COVID-19 based on your symptoms. Some people may self-test (for example through antigen tests). People admitted to hospital may have a nose swab done to confirm the diagnosis.

Follow the advice of your health care provider or local public health authority if you're diagnosed with COVID-19.

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Treating COVID-19

Adults and children with mild COVID-19 symptoms can stay at home while recovering. You don't need to go to the hospital if symptoms are mild.

If you're concerned about your symptoms, consult your health care provider and follow their advice. They may:

Over-the-counter cough and flu medicine should not be given to children younger than 6 years old. It's only safe to do so if your health care provider advises it.

You may be caring for someone at home who has or may have COVID-19. If so, you should follow the appropriate precautions to reduce the risk of illness spreading within your home.

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2026-09-03