Hives (Urticaria)

Hives, also known as urticaria, are raised, itchy welts on the skin that can vary in size and shape. They result from the immune system releasing chemicals like histamine in response to an allergen, which causes small blood vessels to leak and fluid to collect in the skin. This leads to the characteristic swelling and redness. Hives can appear suddenly and may last for a few hours to several days. They can be triggered by foods, medications, stress, infections, or environmental factors. Most cases are minor and resolve on their own, but persistent or severe hives may require medical treatment.