There is no proof that wearing a mask can reduce oxygen levels, also known as hypoxia. The United States Centers for Disease Control and Prevention (U.S. CDC) recommend wearing cloth masks over a surgical mask in public, which are not too tight on our faces and allow for easy breathing.
Even doctors and healthcare professionals wearing N95 masks (which fit very tightly around the face and are made to create a seal around the edge of the mask) are not at risk of hypoxia. However, for any person with preexisting lung or breathing problems in general, they should speak with their doctors about their concerns regarding masks.
Since the World Health Organization and U.S. CDC have recommended wearing masks to prevent the spread of COVID-19, face masks have become a target of political discussions. This is likely due to the fact that in the early months of 2020, face masks were not yet recommended by these groups for a number of reasons, including a lack of evidence that they would be effective (since then research has been conducted and we have proof of their effectiveness) and a general shortage of masks for doctors and healthcare professionals. As more research studies were completed and more evidence made it clear that face masks were effective in helping the spread of COVID-19, the face mask policies also changed.
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.