Hives are swollen, pale red bumps, patches, or welts on the skin that appear suddenly. On darker skin tones, they can appear skin-colored and can be more difficult to see. They can happen because of ...

Cholinergic urticaria (also called cholinergic angioedema or heat bumps) is a reaction that results in tiny hives surrounded by large patches of red skin. They’re related to an increase in your body ...

Pressure urticaria is a form of hives. It develops several hours after applying sustained pressure to the skin, causing painful swelling. Treatment combines pressure avoidance with medications such as ...