Definition

Hay fever is an inflammation of the nasal passages. It is an allergic reaction to substances present in the air. The medical name for hay fever is allergic rhinitis (pronounced ri-NI-tuss).

Description

Hay fever is the most common allergic condition (see allergies entry). An allergic condition is a reaction by the body to some substance that is harmless to most people. For example, most people are not bothered by dust in the air. For other people, however, inhaling dust can cause dramatic bodily changes, such as sneezing, coughing, and itchy and watery eyes.

Between 10 and 20 percent of all people in the United States have hay fever. The condition accounts for about 2 percent of all visits to doctors. The drugs used to treat hay fever make up a significant fraction of both prescription and over-the-counter drug sales each year.

There are two types of hay fever...