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Hives (Urticaria)
Hives are raised, itchy welts on the skin that appear suddenly and may come and go. They are usually caused by an allergic or other trigger releasing histamine in the skin.
Causes & risk factors
- Allergic reactions to food, medicines or insect stings
- Infections
- Heat, cold, pressure or sunlight
- Stress
- Sometimes no identifiable cause
Common symptoms
- Raised, red or skin-coloured welts
- Intense itching
- Welts that move around and fade within hours
- Swelling of lips or eyelids (angioedema)
- Rash appearing suddenly
Tests & diagnosis
- Clinical skin examination
- Allergy testing in selected cases
- CBC
- Thyroid function test
Treatment & management
- Antihistamine medicines as advised
- Avoiding known triggers
- Cool compresses for itch relief
- Stronger treatment for long-lasting (chronic) hives
- Emergency treatment if breathing or swallowing is affected
When to see a doctor urgently
- Swelling of the lips, tongue or throat (emergency)
- Difficulty breathing or swallowing (emergency)
- Hives lasting more than six weeks
- Hives with fever or feeling very unwell
Frequently asked questions
How long do hives last?
Individual welts usually fade within 24 hours, though new ones may appear. Acute hives settle within days to weeks; chronic hives last longer.
When are hives an emergency?
Seek emergency care if there is swelling of the lips, tongue or throat, difficulty breathing or feeling faint, as these can be signs of a severe allergic reaction.
Explore more
Sources & further reading
- World Health Organization (WHO)
- MedlinePlus — U.S. National Library of Medicine
- Ministry of Health & Family Welfare, India
- Indian Council of Medical Research (ICMR)
Reviewed by Dr. Sanjay Anbu, MBBS. MedDroid is an AI medical assistant and can make mistakes. It provides general health information, not a diagnosis or medical advice — always consult a qualified clinician. In an emergency, contact your local emergency number immediately.