How prevalent is brain fog among COVID-19 survivors?

Reviewed by Yoshinori Abe, MD

Internal Medicine

Brain fog is one of the most commonly reported neurological symptoms following COVID-19. Research shows that a significant number of survivors experience lingering difficulties with memory, focus, and concentration—often lasting weeks or months after initial recovery. These cognitive symptoms can affect work performance, daily routines, and overall quality of life.

Because brain fog can stem from many underlying causes—including long COVID, sleep issues, stress, or other medical conditions—it's important to identify what may be driving your symptoms before deciding on next steps. A free, instant, online symptom check can help you quickly assess your situation, understand possible causes, and determine whether it's time to speak with a doctor. It takes just a few minutes and could bring clarity to what you're experiencing.

Reviewed for medical accuracy: 07/15/2026

Quick answers

Frequently Asked Questions

4 answers

The most common questions people search after this page

Concerned about your symptoms?

Start a symptom check

Explanation

Many studies have looked at brain fog in people who have had COVID-19. Brain fog means having a hard time thinking clearly, remembering things, or focusing. One study noted that a sizeable percentage of survivors—sometimes around one in five or more—reported brain fog after their infection. In other words, about 20% or more of COVID-19 survivors have trouble with attention and memory after getting better from the virus.

Other research, especially among those who had to go to the hospital, tells us that brain fog and similar problems like difficulty with concentration and memory loss can stick around for a while. One study even followed patients over time to see how these symptoms changed and found that they gradually improved but were present for months in some cases.

Overall, while the exact numbers can vary from study to study, brain fog is a common issue that many COVID-19 survivors face. If you're experiencing difficulty with memory, concentration, or unclear thinking after COVID-19, consider taking a free symptom checker test to better understand your symptoms and determine if you should seek medical attention.

(References)

Nouraeinejad A. Brain fog as a Long-term Sequela of COVID-19. SN Compr Clin Med. 2023;5(1):9. doi: 10.1007/s42399-022-01352-5. Epub 2022 Nov 24. PMID: 36466122; PMCID: PMC9685075.
Asadi-Pooya AA, Akbari A, Emami A, Lotfi M, Rostamihosseinkhani M, Nemati H, Barzegar Z, Kabiri M, Zeraatpisheh Z, Farjoud-Kouhanjani M, Jafari A, Sasannia S, Ashrafi S, Nazeri M, Nasiri S, Shahisavandi M. Long COVID syndrome-associated brain fog. J Med Virol. 2022 Mar;94(3):979-984. doi: 10.1002/jmv.27404. Epub 2021 Oct 24. PMID: 34672377; PMCID: PMC8662118.
Fernández-de-Las-Peñas C, Cancela-Cilleruelo I, Rodríguez-Jiménez J, Arias-Navalón JA, Martín-Guerrero JD, Pellicer-Valero OJ, Arendt-Nielsen L, Cigarán-Méndez M. Trajectory of post-COVID brain fog, memory loss, and concentration loss in previously hospitalized COVID-19 survivors: the LONG-COVID-EXP multicenter study. Front Hum Neurosci. 2023 Nov 9;17:1259660. doi: 10.3389/fnhum.2023.1259660. PMID: 38021227; PMCID: PMC10665893.

Tell your friends about us.

We would love to help them too.

For First Time Users

What is Ubie’s Doctor’s Note?

We provide a database of explanations from real doctors on a range of medical topics. Get started by exploring our library of questions and topics you want to learn more about.

Was this page helpful?

Purpose and positioning of servicesUbie Doctor's Note is a service for informational purposes. The provision of information by physicians, medical professionals, etc. is not a medical treatment. If medical treatment is required, please consult your doctor or medical institution. We strive to provide reliable and accurate information, but we do not guarantee the completeness of the content. If you find any errors in the information, please contact us.