Allergies 101: Types, Symptoms, Causes & Treatments

Medically Reviewed by Dr. Samantha Miller MBChB

Photo Courtesy: Raquel Arocena Torres/Moment/Getty Images

Approximately 50 million Americans are affected by some form of allergy. Many substances in our environment can trigger allergy symptoms, some of which are easier to avoid than others. An allergic reaction occurs when the immune system mistakenly identifies a substance (an allergen) as harmful to the body. The body’s reaction to this “false alarm” produces a series of unpleasant symptoms.

Depending on the type of allergy, symptoms can occur in the eyes, nose, throat, sinuses, lungs, in the lining of the stomach, or on the skin. Sometimes, the allergic reaction is severe, leading to breathing problems, serious skin rashes, or a life-threatening reaction called anaphylaxis. At other times, allergies symptoms, like itchy eyes and a runny nose, are much more manageable. 

In the same way symptoms vary greatly, avoiding allergies or mitigating exposure to triggers can be tricky. Sometimes, it involves avoiding a particular substance, while, in other cases, patients can treat allergies using over-the-counter medications; medicines prescribed by a doctor; or allergy shots. All of this to say, it's important to be prepared and understand your specific allergies more thoroughly.