Urticaria, commonly known as hives, is a skin condition characterized by raised, itchy welts. These welts can vary in size and may appear anywhere on the body. Urticaria occurs when the body releases histamine in response to allergens, leading to swelling and irritation. Common triggers include certain foods, medications, insect stings, and stress. The condition can be acute, lasting a few hours to days, or chronic, persisting for weeks or longer. While urticaria is usually not serious, it can be uncomfortable and may require treatment with antihistamines or other medications to relieve symptoms and prevent flare-ups.