LearnAboutCovid-19 Health Desk


Does wearing a mask for long periods of time affect the brain causing lethargy, headache, and dizziness because of lack of oxygen?

Last modified on 26 August 2020

What our experts say

The claim that the prolonged use of face masks can cause oxygen deficiency, carbon dioxide intoxication, dizziness, or other health challenges is not grounded in science. Science shows that the risks associated with wearing masks are generally minimal, and the benefits plenty.

Even if a person is wearing an airtight medical grade mask, like an N95 or FFP2 mask, the risks of lethargy, headache, and dizziness are low, even after wearing one for several hours. For an average healthy person wearing a cloth or surgical mask, there is even less risk of these symptoms occurring, because they still allow oxygen to flow out of the mouth and nose freely.

While it might feel like breathing is more difficult in a mask and you are not getting enough air, that is likely a response to stress or anxiety from wearing the mask and can usually be helped by focusing on normal breathing patterns. Shallow breathing, hyperventilation, and breath holding can cause increases in carbon dioxide which leads to headaches and nausea. These symptoms are generally not caused by the use of masks.

Do you need more context? Help is at hand. Ask our experts a question →

Context and background

he claim that the prolonged use of face masks can cause oxygen deficiency, dizziness, or other health challenges is not grounded in science. In fact, healthcare workers often wear masks for long hours in the hospital. There is no evidence that surgical masks or cloth masks cause significant deficiency of oxygen. This information has been primarily circulating on social media among individuals or communities resistant to mask-wearing in general. While masks are restrictive and can feel like they impede air flow, properly designed masks do allow air flow by design, and the feeling of inconvenience or minor discomfort does not equate to health risks such as a lack of oxygen. Low oxygen levels in the blood (hypoxemia) can cause issues in the body to not receive enough oxygen (hypoxia), but both are unlikely to happen as a result of wearing a properly designed mask or face covering.

Wearing a mask is recommended to protect people from community transmission of COVID-19. There are only a few exceptions to this public health recommendation, mostly focused on children under 2 years of age and people with serious medical conditions that can make it difficult to breathe through a mask or remove a mask if necessary. Otherwise, wearing a mask is safe and helpful for preventing the spread of COVID-19.


Glossary Terms

Source of the question

Country question was sourced from


Does this answer vary depending on where you live?

Does this answer vary depending on your race, ethnicity, age, sex or other demographic factors?


  1. From the Frontlines: The Truth About Masks and COVID-19 (American Lung Association)
This database is updated regularly.
Catch up on weekly highlights from award-winning journalist and medical doctor, Dr. Seema Yasmin, by subscribing to our newsletter.

We base our COVID-19 expert contextualizations on information provided by internationally-recognized health organizations, public health researchers and infectious disease experts. Because information in epidemics is constantly being updated, our content is up to date based on the date and time they are published. If you’re looking for medical advice, please contact a healthcare provider, and be sure to review the World Health Organization website for more information about COVID-19.

The data and content on this website are available free of charge under a CC BY-SA license. If you make any additions, transformations, or changes to the dataset please remember to share these under the same license. We would also appreciate you letting us know.