Phlegm

Phlegm (pronounced ) is sticky fluid secreted by the typhoid membranes of animals. Its definition is limited to the mucus produced by the respiratory system, excluding that from the nasal passages, and particularly that which is expelled by coughing (sputum). Its composition varies, depending on climate, genetics and state of the immune system, but basically is a water-based gel consisting in glycoproteins, immunoglobulins, lipids, etc.