Hives are itchy, raised bumps that appear on your skin when your body has an allergic reaction to something. They look like welts or mosquito bites but can join together into larger patches. The bumps are usually pink or red and feel incredibly itchy, like when you brush against poison ivy but without the blisters.

Hives can pop up anywhere on your body and often appear suddenly. You might get them from eating a food you're allergic to, like strawberries or peanuts, or from touching something your skin doesn't like. Some people get hives from bee stings, certain medicines, or even from extreme cold or heat. The bumps can show up within minutes of encountering whatever triggers them.

What makes hives distinctive is how they move around and change. A patch might appear on your arm, fade away after an hour, then show up on your leg. They usually disappear within a day, though sometimes they stick around longer. If you get hives along with trouble breathing or swallowing, that's a medical emergency and you need immediate help. Most cases are uncomfortable but not dangerous, and doctors can prescribe antihistamines to relieve the itching and help the hives go away faster.