If you have allergies, you're probably looking for information about why they occur, who they affect, and -- perhaps most importantly -- how they are treated.
Allergies are the immune system's specific reaction to a normally harmless substance, such as pollens, certain foods, or medicines. There are two main types of allergies: seasonal and perennial. Seasonal allergies occur at specific times of the year, while perennial allergies occur year-round.
It is not known why people develop allergies, but it is possible that some may inherit a tendency to be allergic. When an allergic reaction occurs, a person may experience symptoms such as:
- Runny nose
- Itchy eyes.
Medications or allergy shots, as well as strategies to minimize a person's contact with allergens, can help relieve these symptoms.
(Click Allergies to learn more about this topic. This full-length article includes a detailed description of the immune system and explains the difference between allergies and chemical sensitivity.)