Allergy Overview

What Causes Allergies?

Your immune system is your body’s first line of defense against germs and bacteria. Comprised of cells, proteins, tissues and organs, it is essential in maintaining your health and preventing infections. When a threat is perceived, the immune system responds by attacking the substances that are invading the body.

Allergies are the result of the immune system responding in an over protective manner to a harmless substance. When an allergen is encountered, antibodies – proteins designed to protect against foreign invaders – are produced. These trigger the release of chemicals called histamines, which are responsible for the telltale symptoms of allergies.

What Are the Symptoms of Allergies?

Allergies may be seasonal or occur year-round. Hay fever caused by pollen from grasses, trees and weeds is the most common seasonal allergy. Symptoms include:

• Stuffy and/or runny nose
• Sneezing
• Itchiness in the nose and throat
• Postnasal drip
• Itchy, watery eyes
• Pressure in the ears
• Fatigue

Year-round allergies produce the same symptoms; common ones are mold, dust mites, pet dander, environmental irritants like smog or smoke, medications and chemicals. Insect stings and bites fall in this category, too.They can produce a life-threatening allergic reaction known as anaphylaxis.