Mucus membranes coat most of the passages that carry air into the lungs. The bronchi, the branches within the lungs, are also producers of mucus. Dry air is not as easily used by the human organism. Mucus keeps the nasal passages moist and moistens the air for use by the body.

The mucus is moved by the cilia, little by little, upwards into the throat. Cilia are little hairs in the entire respiratory system from the lowest part of the lungs to the end of the nose and throat. This is a constant process all day and night. At night their job is easier because they are not working against gravity, as they are during the day. This is why there is more mucus upon awakening than any other time of the day.

The mucus is mostly swallowed, and only a small amount actually goes out the nose. The mucus coming out of the nose is usually not the mucus coming out of the lungs. It comes from the sinus passages and the nose itself, for the nose also produces mucus in order to combat pollutants in the air. The mucus that does not come out of the nose moves into the gastrointestinal tract by swallowing in the back of the throat. The digestive juices kill the microbes in the mucus. Mucus is broken down and recycled.

Smokers develop a great deal of mucus. If they stop smoking, a cleansing period ensues with headaches (from toxins in the mucus), nausea (excess mucus in the stomach upon awakening), and coughing. If one does not stop smoking, coughing is not due to cleansing. It is due to irritation from the smoke, coal tar, 96 chemicals normally found in most cigarettes, and the destruction of cilia. The smoke of cigarettes completely destroys cilia, and this takes away the body’s avenue for removing mucus up and out of the lungs to the throat. After one stops smoking, the cilia are gradually regenerated and mucus movement can return to normal.