Hives (Urticaria) Make an Appointment Find a Doctor Ask a Question Reviewed by Christine B. Cho, MD (April 01, 2019) What are hives? Most of us have heard of hives. Many people develop hives at some point in their lives. The scientific name for hives is urticaria. A hive is a raised, extremely itchy "wheal" or bump on the skin with surrounding skin redness. Hives often last for less than a day and usually clear up within a few hours. They may be small bumps or large and irregularly shaped areas. Hives typically do not leave a mark or scar and are not painful. Hives can occur in any location, but if they occur in some areas, such as the eyelid or ear, they can appear to be very swollen. They can also be associated with other areas of swelling, also called angioedema. Hives (urticaria) can be acute or chronic. Acute urticaria is when someone has hives for less than six weeks. If someone has hives for a longer period of time, he or she is diagnosed with chronic urticaria. Typical Hives (Urticaria) Anyone at any age can get hives. Hives are often extremely itchy and transient; hives last for hours, not days. Hives are typically asymmetric in distribution (meaning that one half of the body does not mirror the other half of the body). There are multiple causes of hives. Programs & Services Allergy Treatment Programs (Adult) Clinical Trials For more than 100 years, National Jewish Health has been committed to finding new treatments and cures for diseases. Search our clinical trials.