(WUTR) — The effects of COVID impact everyone differently, and that’s the same for those who recover. But there’s one symptom that’s gained a lot of attention recently, and it’s called COVID Brain Fog.

“They feel slower, they feel like they can’t concentrate as well. I mean it’s a spectrum so you know some people just have mild things. Others can be very significant including being forgetful and things like that,” said Dr. Kent Hall, Chief Physician Executive at Mohawk Valley Health System.

This can affect anyone who’s had COVID, and those who were very ill are more likely to develop brain fog. Symptoms can last anywhere from a few days to months after recovering. The cause is still unknown but scientists have theories.

“Your body is still in a mode of I need to fight something off. Your body is diverting energy to resources to fight the infection. And one of the places where it diverts energy resources from is your brain,” Hall said.

Another theory suggests that tiny blood clots form in the brain’s vessels that slows down its functions. Researchers don’t know how many people have or had COVID brain fog, but dr. Hall says if you’re experiencing symptoms to contact your doctor.

“Getting checked out to make sure that there’s nothing else going on, and honestly, to be monitored over time is really the best thing,” Hall said.