Urticaria, commonly known as hives, is a skin condition that many people experience at least once in their lifetime. It appears as raised, red, very itchy patches on the skin that can be small, large, round, or even merge together into bigger areas. These welts often show up after scratching and can appear anywhere on the body.
The condition occurs when certain cells in the body—called mast cells—release histamine and other chemicals into the bloodstream. This causes tiny blood vessels in the skin to leak fluid, creating the swollen, itchy marks that characterize urticaria.
