Can COVID-19 Cause Brain Fog?


Most of the headlines around COVID-19 have focused on respiratory side effects and symptoms — coughing, wheezing and shortness of breath. But new evidence shows that the virus’ effects may go beyond the lungs. It may also have an impact on brain and mental function.

“There’s still so much that we don’t know about COVID-19, but we’re seeing some patients complain of a brain fog,” says Barry Wendt, MD, an internal medicine specialist with St. Elizabeth Healthcare. “Patients tell us that they have trouble concentrating, difficulty finding words or even short-term memory loss.”

We spoke with Dr. Wendt to learn more about the connection between the virus and mental function and whether there’s a way to treat this frustrating side effect.

What is brain fog?

There is no official disease diagnosis for brain fog, Dr. Wendt explains. It’s a side effect caused by certain health conditions, infections and some procedures or treatments.

Brain fog can make your thoughts feel “hazy” and cause:

  • Confusion.
  • Difficulty concentrating or focusing on a task.
  • Fatigue.
  • Memory issues (usually short-term memory problems).

Unfortunately, no test can diagnose brain fog — it doesn’t show up in a blood sample or imaging scan. However, your doctor may ask you to undergo some tests to make sure an underlying condition isn’t causing your symptoms.

For example, thyroid problems and urinary tract infections can cause brain fog, especially in older adults.

“This process is called diagnosis of exclusion,” Dr. Wendt says. “There are a lot of diseases other than COVID-19 that can cause these issues. So we want to rule those out.”

What’s the connection between COVID-19 and brain fog?

Although there’s still a lot to learn about COVID-19 side effects, doctors think that blood flow issues may cause brain fog.

“The virus seems to make your body develop blood clots more easily. This makes us wonder if brain fog stems from problems with your blood vessels and how blood gets to your brain,” Dr. Wendt explains.

Doctors have found unusual cells in the brains of COVID-19 patients. These cells, called megakaryocytes, are usually found in bone marrow. Megakaryocytes produce platelets, which help blood clot.

“We’re not sure what significance this has, but we think these megakaryocytes may be playing a role in brain fog symptoms,” Dr. Wendt says.

Does brain fog affect everyone with COVID-19?

Everyone experiences different COVID-19 symptoms, which has been a challenge in detecting and treating the disease. However, Dr. Wendt says that patients who complain of brain fog tend to be the ones who are sicker with COVID-19.

“Patients who are hospitalized or end up in the intensive care unit seem to be more susceptible to mental fatigue and confusion,” he says. However, Dr. Wendt also points out that many patients in the ICU are being treated for other health conditions that could contribute to the brain fog symptoms. 

It’s important to note that doctors don’t know the long-term effects of COVID-19. More research (and time) is needed to determine if COVID-19-related brain fog can cause other health conditions down the line.

Can you treat brain fog?

There’s no specific treatment or medicine for brain fog. But there are some lifestyle adjustments you can make to ease the symptoms. These include:

  • Avoid smoking.
  • Exercise regularly.
  • Get plenty of sleep.
  • Limit the amount of alcohol you drink.
  • Take all medications as directed by your doctor.
  • Work with your doctor to treat any underlying health conditions like diabetes or high blood pressure.

“I also encourage patients to work on puzzles and brain games when they can,” Dr. Wendt says. “It’s important to keep your mind active.”

What should I do if I think I have brain fog?

If you have any symptoms of brain fog, make sure to talk to your doctor. If it’s safe to do so, see your doctor in person for an exam and evaluation. Your doctor may also ask you to undergo some basic lab tests to rule out other conditions that can cause brain fog.

Dr. Wendt recommends keeping up a healthy lifestyle and managing any health conditions you have to avoid worsening brain fog symptoms.

“Get plenty of exercise, rest when you need it, avoid any harmful substances or activities and keep using your brain,” he says.

Learn more

There’s still a lot to learn about the long-term side effects of COVID-19. Don’t hesitate to reach out to your doctor with any questions or concerns. You can schedule a visit to talk with your primary care doctor or search for a St. Elizabeth doctor in your area with our provider directory.