Fifty million Americans suffer from some type of allergy. With so many different symptoms and so many varieties of allergies, people have a lot of questions.

We've got answers to your most frequently asked questions:

Q. What exactly does allergy mean?

A. The Allergy and Asthma Foundation of America says an "allergy is characterized by an overreaction of the human immune system to a foreign protein substance ('allergen') that is eaten, breathed into the lungs, injected, or touched."

Our body comes in contact with foreign substances all day long. Most allergens are harmless and most people are not affected by them. For some people however, an allergen sets off a series of physical reactions that manifest as noticeable symptoms. That's called an allergy or allergy attack. If you are allergic to a substance, such as cat fur, your immune system reacts to it as if it were a pathogen (a foreign harmful substance), and works to destroy it.

Q. What kinds of allergies are there?

A. Many. People can be allergic to plants, pollen, medicines, chemicals, animals, foods, fabrics, lotions, cosmetics, and cleaning products. If they have seasonal allergies, they may find that weather and plant conditions at certain times of year cause symptoms to appear. Some people are allergic to many things and may not be able to identify all of them while others only experience allergic symptoms when they come into contact with one or two very specific substances.

Q. What does it feel like to have allergies?

A. It depends on the type of allergy, but common symptoms include:

  • Itchy, swollen, watery eyes
  • Nasal congestion
  • Runny or itchy nose
  • Itchy face
  • Hives
  • Rashes
  • Itchy, peeling, or flaking skin
  • Blisters
  • Sneezing
  • Coughing
  • Itchy or tingling sensation in the mouth, throat, or ears
  • Swelling of the tongue, lips, or throat
  • Vomiting
  • Diarrhea
  • Stomach pain
  • Headache
  • Shortness of breath
  • Chest tightness
  • Difficulty breathing
  • Wheezing
  • Asthma
  • Low blood pressure
  • Dizziness
  • Loss of consciousness

Q. Are allergies dangerous to your health?

A. Most of the time, allergies are simply annoying, unpleasant and treatable, but sometimes, they can be very dangerous. Anaphylaxis is a serious allergic reaction that happens quickly, can be life threatening and must be treated as a medical emergency. It usually presents with several different symptoms that occur minutes or hours after exposure to a specific allergen.

Q. Can allergies be cured?

A. "Immunotherapy—allergy shots or allergy drops—can indeed change the natural history of allergic disease," says Karen Calhoun, MD, professor of Otolaryngology at The Ohio State University. "Not only does it change blood and skin testing results from positive to negative, but it also reduces the development of future allergies and, in children, reduces the risk of progressing to allergic asthma. This treatment is focused, specific, and highly successful.

Q. How are allergies treated?

A. In most cases, treatment revolves around avoiding exposure to known allergens and preventing symptoms from becoming extreme. That might mean avoiding specific animals, pollens and plants, dust and chemicals, or certain foods. It might mean wearing a bracelet to remind yourself and others that you have drug allergies. If avoiding allergy triggers isn't feasible however, many people with allergies treat symptoms with medicines including antihistamines—(medications that block or treat allergic symptoms), steroids, decongestants, and others. Many people find symptom relief with alternative therapies like acupuncture. Many others see allergy specialists for treatments that include injections with tiny amounts of known allergens that encourage the body's immune system to build up tolerance.

General and family practice physicians can treat most types of allergies and allergy specialists can treat advanced cases.

Karen H. Calhoun, MD, FACS, FAAOA, reviewed this article.



"Allergy Facts and Figures." Allergy and Asthma Foundation of America. Page accessed September 2, 2014.

"Allergy Statistics." American Academy of Allergy, Asthma and Immunology. Page accessed September 2, 2014.