When you cough up phlegm where is it coming from?

Phlegm is a thick, sticky substance that is produced in the lungs and throat. It is made up of mucus, which is a natural substance that helps to protect the lungs from irritation and infection, as well as dead cells and other debris. When you cough up phlegm, it is because the body is trying to expel these substances from the lungs.

There are a number of reasons why you might cough up phlegm, including:

* A cold or flu: Colds and flu are common respiratory infections that can cause inflammation and mucus production in the lungs. This can lead to coughing up phlegm.

* Sinusitis: Sinusitis is an inflammation of the sinuses, which are the air-filled spaces behind the forehead, nose, and cheekbones. Sinusitis can cause mucus to drain into the throat, which can lead to coughing up phlegm.

* Allergies: Allergies can cause inflammation and mucus production in the nose, throat, and lungs. This can lead to coughing up phlegm.

* Asthma: Asthma is a chronic respiratory condition that causes inflammation and narrowing of the airways. This can lead to coughing up phlegm.

* COPD: COPD is a chronic respiratory condition that causes damage to the lungs. This can lead to coughing up phlegm.

* Smoking: Smoking can irritate the lungs and cause inflammation. This can lead to coughing up phlegm.

If you are coughing up phlegm, it is important to see a doctor if the phlegm is:

* Green or yellow in color

* Bloody

* Foul-smelling

* Accompanied by a fever

* Accompanied by shortness of breath

* Accompanied by chest pain

These symptoms could be a sign of a more serious medical condition.