Medically reviewed by Susan Russell, MD Key Takeaways Coughing up white mucus can be a sign of an upper respiratory infection or chronic conditions like COPD. Viral infections that cause white mucus ...

Healthy phlegm is usually clear and runny, but many different health conditions can change the consistency or color. Phlegm, also called sputum, is mucus produced by your lungs that helps protect your ...

Drinking plenty of fluids can help decrease the thickness of phlegm and make it easier to remove. Bloody, brown, white, yellow, or green phlegm may be a sign of an underlying condition or infection.

Mucus is a normal part of the lungs. But smoking and other issues can cause too much mucus to collect there. (Photo Credit: iStock/Getty Images) Your body makes about a liter (approximately 1 quart) ...

Snot is made up of water, proteins, antibodies, and dissolved salts, explains Jonathan Parsons, M.D., a professor in the Department of Internal Medicine at The Ohio State University Wexner Medical ...