Mucus is a thin, clear, sticky substance that lines many parts of your body including your mouth, sinuses and lungs. Mucus plays a key role in protecting your lungs and airways from harmful irritants.
Key Facts:
- Sputum and phlegm are other names sometimes used to refer to the mucus in your lungs and airways.
- Changes in mucus amount, thickness or color may be a sign of infection or another health condition.
- A sputum culture is a test that checks for bacteria or other types of germs that may be causing an increase in mucus.
Why Do We Have Mucus?
In healthy lungs, your airways are lined with a thin layer of mucus and tiny hair-like structures called cilia. Together, mucus and cilia help trap irritants, like germs, dust or smoke, before they can get into your lungs. When you cough, mucus helps remove these irritants from your body. This protects you from germs that may cause an infectious lung disease like the flu or COVID-19.
If you are living with a chronic lung disease like COPD, cystic fibrosis or bronchiectasis it may mean you have more, thicker or stickier mucus in your airways and lungs. When mucus builds up in your airways it can make breathing harder and increase your risk of getting a lung infection.
When Should I Seek Medical Attention?
If an increase in mucus production is new for you or seems to be getting worse, it could be a sign of a lung infection. Other signs or symptoms may include fever, a cough that produces mucus, shortness of breath or chest pain.
If your healthcare provider suspects you have a respiratory infection, they may order a sputum culture to analyze a sample of your sputum or phlegm for bacteria or fungi. A sputum culture can also help diagnose respiratory conditions like pneumococcal pneumonia or bronchiectasis. Depending on your symptoms, they may also order a chest X-ray or CT scan.
The color of your mucus can provide clues about what may be happening in your lungs and airways. Healthy mucus color is usually clear. Mucus that is white, yellow or green may be a sign of an infection. Pink, red, dark brown or black mucus can sometimes be a sign of a more serious health condition. If you notice changes in the color of your mucus, especially if it is persistent or occurs along with other symptoms such as shortness of breath or fever, contact your healthcare provider.
Treating and Managing Mucus
Once you and your healthcare provider have identified the cause of your excess mucus production, there are steps you can take to help manage symptoms and clear mucus from your lungs and airways. Together, you can develop a treatment plan and monitor how well it works.
Your healthcare provider may recommend you try to:
Controlled coughing loosens mucus and helps it move through the airways. One technique is called huff cough method.
Huff Cough Method:
Get started by sitting upright in a chair with both feet on the floor. To inhale, take a deep breath through your nose.
When you breathe out, open your both and make a “huff” sound in your throat. Huff 2-3 times as you breathe out. Relax and repeat as needed.
You can lie down in different positions to help clear the mucus. When you lie down with your chest lower than your abdomen, it can help drain the extra mucus. To cough up the mucus, sit upright and use the huff cough technique.
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Page last updated: July 24, 2026
