Hives, also called urticaria, are raised, itchy welts on the skin. They may look red, pink, skin-colored, or slightly swollen. Hives can appear suddenly, move around the body, change shape, disappear, and then come back in a different area. Many cases of hives are mild and temporary, but hives can sometimes be part of a serious allergic reaction. It is important to know when hives can be managed with supportive care and when urgent help is needed. What do hives look like? Hiv