Coughing up mucus (or phlegm) can have several common causes, mostly related to the body's response to irritation or infection in the respiratory tract. Some of the primary reasons include:
- Upper respiratory infections such as colds, flu, and sinus infections cause the body to produce mucus to trap and clear germs, leading to coughing up phlegm as the body tries to rid itself of excess mucus and infection.
- Allergies can cause mucus production in response to irritants like pollen or dust, triggering a cough that brings up mucus.
- Asthma and chronic lung conditions like chronic obstructive pulmonary disease (COPD) can cause inflammation of the airways and increased mucus production.
- Postnasal drip, where mucus from the nose drips down the back of the throat, can irritate the throat and cause coughing up mucus.
- Gastroesophageal reflux disease (GERD), where stomach acid irritates the throat, can cause a cough with mucus.
- More serious infections such as bronchitis or pneumonia may also produce productive cough with mucus.
- Smoking and exposure to irritants can cause chronic irritation and mucus production.
The color, amount, and persistence of mucus can help indicate the underlying cause, and if it is accompanied by other symptoms or persists, medical evaluation is recommended to diagnose and treat accordingly.
If the mucus production and coughing are new, mild, and occur with cold symptoms, it usually resolves on its own. However, persistent or severe symptoms, colored mucus (such as green or yellow), or accompanying symptoms like fever or shortness of breath warrant seeing a healthcare provider.
