When your nose and sinuses become congested, the amount of air that can reach your lungs is compromised. The body’s natural method to compensate for this lack of air intake is to allow us to breathe through our mouths. But mouth breathing is not normal: We are intended to breathe only through our nose. Yet many of us have been mouth breathers our whole lives.
Remember, the air that reaches our lungs must be heated, humidified, and filtered. The air that we breathe through our mouths will not have passed through the sinuses and, therefore, will not be cleansed before entering the lungs. Mouth breathers unknowingly allow dirt, infection, and inflammatory agents to enter their system, which is not good for the lungs or any part of the body.
You can tell when someone has trouble breathing through his or her nose because the mouth will be kept open, even slightly, at all times. This slight opening of the lips is referred to as breathing through “pursed” lips. Sometimes the obstruction is so bad that the mouth is always significantly open, giving the person an odd, quizzical look on his or her face. Chapped lips are another sign of a mouth breather. When you breathe through your mouth, the dry air will make your lips chapped. When your lips become chapped, you will have a tendency to lick them and this will make them more chapped. A mouth breather may have chapped lips even in the summer, when the air is moist with humidity.