Why can't you breathe from your mouth?

You can breathe through your mouth; however, it is not as efficient as nasal breathing. The nose filters, warms, and humidifies the air, protecting the lungs from irritants and pathogens. Breathing through the mouth bypasses these functions, which can lead to dryness in the throat and lungs and may increase the risk of respiratory infections. Additionally, chronic mouth breathing can lead to dental issues and other health problems.