What causes plegm?

Causes of phlegm

Phlegm is produced when the membranes that line the respiratory tract produce more mucus than normal. This can be caused by a number of factors, including:

* Allergies: When you have an allergy, your body's immune system overreacts to a foreign substance, such as pollen or dust. This reaction can cause inflammation of the respiratory tract, which produces phlegm.

* Cold and flu: Viruses that cause the common cold and flu can irritate the respiratory tract and cause it to produce more mucus.

* Sinusitis: This is an inflammation of the sinuses, which are air-filled spaces in the head. Sinusitis can cause pressure and pain in the face, as well as a runny nose, nasal congestion, and phlegm production.

* Bronchitis: Bronchitis is an inflammation of the bronchial tubes, which are the tubes that carry air to and from the lungs. Bronchitis can be caused by viruses or bacteria, and it can cause cough, wheezing, chest tightness, and phlegm production.

* Pneumonia: Pneumonia is an infection of the lungs. It can cause cough, fever, chills, shortness of breath, and phlegm production.

* Smoking: Smoking irritates the respiratory tract and can cause it to produce more mucus.

* Air pollution: Air pollution, such as smog and smoke, can irritate the respiratory tract and cause it to produce more mucus.

* Certain medications: Some medications, such as birth control pills and asthma medications, can cause side effects that include increased mucus production.