Concept: 14- Why do we get a runny nose?

A runny nose, also known as rhinorrhea, occurs when the tissues lining the nasal cavity produce excess mucus. This can be caused by a variety of factors, including:

1. Cold or flu: A viral infection, such as the common cold or flu, is one of the most common causes of a runny nose. When the body detects a virus, it produces excess mucus as a way to trap and eliminate the virus.
2. Allergies: Allergic reactions to substances such as pollen, pet dander, or dust can cause the body to produce excess mucus as a way to flush out the allergen.
3. Sinusitis: Inflammation of the sinuses can cause the tissues in the nose to produce excess mucus.
4. Environmental irritants: Exposure to irritants such as smoke, pollution, or chemical fumes can also cause a runny nose as the body tries to eliminate the irritant.
5. Spicy foods: Eating spicy foods can cause the nasal tissues to produce excess mucus as a way to protect against the irritants in the food.

In general, a runny nose is the body's way of protecting itself from foreign substances and irritants. While it can be annoying, it is usually a sign that the body's immune system is working to keep us healthy.