What Is an Allergy?

An allergy is when your immune system reacts to a foreign substance, called an allergen. This reaction causes specific clinical symptoms. The allergen could be something you eat, inhale into your lungs, inject into your body, or touch.

An allergic reaction can cause coughing, sneezing, hives, rashes, itchy eyes, a runny nose, swelling, and a scratchy throat. In severe cases, it can cause low blood pressure, breathing trouble, asthma attacks, and even death if not treated promptly and appropriately.

There is no cure for allergies. You can manage allergies with proper education, prevention, and medical treatment.

Allergies are among the country’s most common, but overlooked, diseases. 

How Common Are Allergies?

More than 100 million people in the U.S. experience various types of allergies each year. Common examples include seasonal allergies, eczema, and food allergies.

Nearly 1 in 3 U.S. adults and more than 1 in 4 U.S. children have a seasonal allergy, eczema, or food allergy. 

How Many People Seek Medical Care for Allergies?

Allergic conditions are one of the most common health issues affecting children in the U.S.

Each year in the U.S., it is estimated that anaphylaxis (a severe allergic reaction) to food results in 90,000 emergency room visits. 

How Many People Die from Allergies?

The most common triggers for anaphylaxis are medicines, food, and insect stings.5 Medicines cause most allergy-related deaths.

Older adults in the U.S. have the highest rates of death due to allergic reactions to medicines, food, or unknown allergens.