Urticaria, or hives, is a widespread skin condition affecting around 20% of people at some point in their lives. It presents as intensely itchy, raised patches on the skin called weals, which can vary in shape and sometimes merge into larger areas. These welts often develop after scratching and may appear anywhere on the body. The condition occurs when mast cells release histamine and other chemicals into the bloodstream, causing fluid to leak from capillaries and produce the characteristic swelling. Although individual hives typically fade within 24 hours, the underlying condition can linger.

Urticaria may be accompanied by angio-oedema, a deeper, more painful swelling beneath the skin that usually affects soft tissues such as the lips, eyelids, and mouth. This swelling can last longer than hives and may signal hereditary angio-oedema if it occurs without visible hives, requiring specific diagnosis and treatment. Urticaria is categorized into three types: acute (lasting less than six weeks and often linked to a clear trigger), chronic (persisting beyond six weeks with no known cause), and physical (caused by external stimuli like cold, heat, or pressure). Triggers include allergies, infections, and emotional stress. While most cases resolve naturally, ongoing or severe symptoms may be managed with treatments like antihistamines, corticosteroid tablets, or soothing menthol creams.