Hives, also known as urticaria, are red, itchy bumps or welts that can appear on any area of the skin. Hives can appear suddenly without any cause or they can be triggered by eating certain foods, stress, or other allergens. About 1 in 5 people experience hives at some point during their lifetime, making it a fairly common condition.

Hives are considered chronic if they last for six weeks or longer. Chronic spontaneous urticaria, or CSU, is the medical term for chronic hives that have no known cause.^1,2

Read on to learn more about CSU.

By the Numbers

Causes and Symptoms

Living with CSU

Seek Help from an Allergist

If you or someone you know is suspected of having CSU, you can find an allergist in your area and address your symptoms. https://allergist.aaaai.org/find/