How COVID-19 affects the brain
COVID-19 may be best known for how it affects the lungs, making it hard for some people to breathe. But the illness can also mess with other parts of the body—including the brain.
Some of these effects on the brain and nervous system are experienced by long-haulers—people who struggle with symptoms months after their infection.
These can include:
Lost sense of taste and smell. This is one of COVID-19's stranger symptoms. It happens when the virus affects nerve cells in the nose and mouth. It may take weeks or months to recover these senses.
Brain fog and headaches. Some people who've recovered from COVID-19 have reported having trouble thinking or concentrating—sometimes called brain fog. Other people experience headaches, fatigue and symptoms of nerve damage in their feet.
More severe effects. Some people who have been hospitalized with severe COVID-19 develop delirium, a form of mental confusion.
COVID-19 can also cause other neurological conditions, including memory problems and strokes.
Why does COVID-19 affect the brain?
Scientists are still learning about how COVID-19 affects the brain. We don't have all the answers yet. But here are some ways it might happen:
Inflammation in the brain. Researchers have studied the brain tissue of people who died of COVID-19. They found signs of damaged and leaky blood vessels. They also saw evidence of inflammation (the body's response to germs or injuries) without the virus having infected the brain. This suggests that the body's inflammatory response to COVID-19 infection—not the virus itself—may be to blame for some symptoms.
Brain infection. Could the virus itself infect and harm the brain or nervous system? It would have to cross a protective blood-brain barrier of cells first. A study done in mice suggests that the viral spike protein may be able to do that—in mice, at least.
Blood clots. COVID-19 can also cause blood clots in some cases. These may travel to the brain and cause a stroke.
Talk to your doctor
If you think you have lingering symptoms from COVID-19, tell your doctor. There may be treatments or lifestyle changes that could help.
To learn more about COVID-19, visit our Coronavirus health topic center.