Sputum color

Mucus in the lungs is known as phlegm or sputum. It is a common symptom in chronic lung diseases such as COPD (including chronic bronchitis and emphysema), cystic fibrosis, bronchiectasis, NTM lung disease or asthma.

In undamaged airways, oxygenated air moves easily through tubes, helped along by tiny hairs that line the airways called cilia.

Mucus has an important role in your lung’s immune response because it traps irritants in your airways and helps allow your body to expel them through coughing. This helps protect you from infection. You can see how this works in our new animation that explains how a cough works, and the important part that mucus plays in clearing your airways from smoke, germs, dust and chemicals.

“Coughing up mucus is not normal, and it should raise the alarm that something is wrong.”