The mucus comes from the conjunctiva which is the transparent tissue covering the whites of the eye and internal surface of the eyelids. This mucus forms the innermost layer and helps the tears to ...

Mucus is a substance that lines the moist surfaces of your body, including the lungs, sinuses, mouth, stomach, intestines, and eyes. “It is mainly a combination of water and large molecules ...

When a person has black or dark-colored mucus, they may have inhaled potentially harmful pollutants. Coughing up black mucus may also be due to an underlying infection or condition. Mucus serves ...

Mucus provides an essential barrier for humans that protects vulnerable surfaces in the lung, intestinal, eye and reproductive tissues from invasion by bacteria, viruses, allergens and irritants.

Medically reviewed by Robert Burakoff, MD Mucus in stool is normal, but it's not usually visible to the naked eye. When it is ...