Wearing a cloth mask will not cause dizziness, lightheadedness, or headaches (also known as hypercapnia or carbon dioxide toxicity). Carbon dioxide passes through the mask, it does not accumulate inside the mask. The claim that prolonged wearing of face masks can cause oxygen deficiency, dizziness or other health problems is not based on science. In fact, health workers often wear masks for long hours in the hospital.
There is no evidence that surgical masks or cloth masks cause significant oxygen deficiency. This information has been circulating mainly on social networks among people or communities that are resistant to the use of masks in general. While masks are restrictive and may appear to prevent airflow, properly designed masks allow airflow by design, and the feeling of minor discomfort or discomfort does not equate to health risks, such as lack of oxygen. Low blood oxygen levels (hypoxemia) can cause problems for the body not getting enough oxygen (hypoxia), but both are unlikely to occur as a result of wearing a properly designed mask or face covering.
And masks can make you feel claustrophobic and anxious, leading to hyperventilation (fast breathing). This will cause you to feel dizzy, lightheaded, numbness and tingling in your lips and possibly spasms in your hands and feet. You may be hyperventilating and you don't even realize it. While wearing a mask for long periods of time could actually make headaches worse, you've probably heard other statements about the dangers of wearing masks that are a little less substantiated.
Most worrying is the suggestion that wearing a mask causes hypercapnia, a condition caused by having too much carbon dioxide in your blood. Symptoms of mild hypercapnia include dizziness, fatigue, headaches, and shortness of breath. In severe cases, it can cause muscle spasms, fainting, seizures, and even coma.