A higher-than-normal amount of phlegm can build up in your nose, throat, and lungs when you are sick. This build-up may cause coughing and discomfort. Bloody, brown, white, yellow, or green phlegm ...
For instance, “with lung infections, lying down helps the cilia [little ‘hairs’ in our lungs] to more effectively move mucus out of the lungs, and the cough reflex is our body's attempt to ...