Home > Encyclopedia of Medicine > Nasal Polyps

Definition

A polyp is any overgrowth of tissue from a surface. Polyps come in all shapes—round, droplet, and irregular being the most common.

Description

Nasal polyps tend to occur in people with respiratory allergies. Hay fever (allergic rhinitis) is an irritation of the membranes of the nose by airborne particles or chemicals. These membranes make mucus. When irritated, they can also grow polyps. The nose is not only a passageway for air to reach the lungs; it also provides the connection between the sinuses and the outside world.

Sinuses are lined with mucus membranes, just like the nose. Polyps can easily obstruct the drainage of mucus from the sinuses. When any fluid in the body is trapped...