Pleurisy, also known as pleuritis, is the inflammation of the pleura tissues that separate the lungs from the chest wall. It can be caused by respiratory infections, inherited genetic conditions, or certain medications. Public health and medical experts have not found pleurisy to occur as a result of wearing a mask or face covering to prevent COVID-19 transmission. Mask-induced pleurisy has not been validated in scientific or medical literature. The Chief Medical Officer of the American Lung Association stated that there is not a "medically plausible mechanism for mask-wearing to cause pleurisy."

Regarding concerns about wearing masks for 3 hours or longer leading to pleurisy or other health issues, healthcare workers have been wearing tighter masks for much longer than 8 hours a day without negative side effects.

Wearing masks is generally considered safe for children and adults. There are a few exceptions, for very young children (under 2 years of age in the U.S.) and people with health conditions that make it difficult to wear a mask (ex. certain pre-existing pulmonary or cardiac issues, mental health conditions, developmental disabilities). For the vast majority of people, wearing masks are an effective way to help reduce COVID-19 transmission without causing any major side effects, as long as masks are kept clean and used correctly.

Public health experts and doctors recommend wearing face coverings and masks to help prevent COVID-19 transmission between people. Beyond exceptions for very young children (under 2 years of age in the U.S.) and people with medical conditions that can make it difficult to breathe through a mask, wearing masks is widely considered safe with minimal side effects. Unfortunately, misinformation has been spreading through social media and other channels about the use of masks, with many claims about risks that have not been scientifically verified. One such claim has been spreading on Facebook, along with a photo of a dirty used mask, about the risks of pleurisy for children wearing masks for more than 3 hours. Public health experts have responded that this claim about pleurisy is false.

For children and adults, masks should be kept clean, with a new or sanitized mask used for each public outing. People can see what type of mask is the right size for their face and fits comfortably for prolonged use. Some people also choose to reduce and shorten public outings as much as possible to help minimize the amount of time a mask needs to be worn. Children and others who may need assistance can be monitored to ensure they are putting on, wearing, and taking off masks correctly.

It is important to remember that masks are a reduction measure that lowers the chances of infection, which is different from risk avoidance measures that completely eliminate risks. Masks should be used in combination with other preventative measures, like washing hands and maintaining physical distance.