Urticaria, commonly known as hives, is a widespread skin condition affecting about one in five people at some point in their lives. It is characterized by intensely itchy, raised patches called weals, which may be round, ring-shaped, or merged together. These typically appear after scratching and can occur anywhere on the body. The reaction happens when mast cells release histamine and other chemicals into the bloodstream, causing capillaries to leak fluid, which results in the formation of welts. Though these hives often disappear within 24 hours, the condition itself may linger longer.

Urticaria is frequently accompanied by angio-oedema—swelling beneath the skin, particularly around the lips, eyelids, or inside the mouth. This swelling tends to be more painful and lasts longer than hives. If angio-oedema occurs without visible hives, it might suggest hereditary angio-oedema, a separate condition that requires specific diagnosis and treatment. Urticaria is generally classified into three types: acute (lasting less than six weeks and often with a known cause), chronic (lasting more than six weeks with no clear trigger), and physical (caused by factors like cold, pressure, heat, or sunlight). Common triggers include allergens, infections, and stress. While mild cases often resolve without treatment, more severe or persistent cases may need medical management using antihistamines, corticosteroids, or soothing menthol creams to reduce itching and discomfort.