Urticaria (hives) affects about 1 in 5 people at some point in life. It causes red, raised, very itchy skin patches that can appear anywhere on the body and sometimes join together.
It happens when the body releases histamine, leading to fluid leaking into the skin and forming welts. In some cases, swelling under the skin (angioedema) can also occur, often affecting lips, eyelids, or mouth.
Hives usually disappear within 24 hours, but some cases last longer:
- Acute urticaria (under 6 weeks)
- Chronic urticaria (over 6 weeks)
- Physical urticaria (triggered by heat, cold, pressure, or sunlight)
Common triggers include allergies, infections, stress, or certain medications.
Most cases clear on their own, but antihistamines or creams can help with itching. Persistent symptoms should be checked by a doctor.
