Hives are usually caused by an allergic reaction although you can get them from an infection, physical irritations (such as heat, cold, light or friction), insect bites, chemical exposures or emotional reaction. (Yes, your hives can be a purely psychosomatic phenomena.)

Hives may also be referred to as urticaria, welts or wheals. They are characterized by a red, raised, itchy skin rash that tends to occur in round patches. Unlike an insect bite or sting, each hive can be as small as a few millimeters or as large as several inches. Hives usually occur in a batch, with several clustered on the face or extremities (arms, hands, legs or feet).

Hives are a result of the release of histamine in the body - this is their link to allergies. The release of histamine and other allergy-related chemicals cause both skin inflammation and fluid accumulation. This causes the distinctive round or oval shape to the patchy rash.

In many cases, hives are not treated because they don’t last long. If hives are stubborn, a physician may treat hives with antihistamines, corticosteroids or both of these drugs. If the problem is chronic, a wide range of treatments may be suggested, including antihistamines and corticosteroids as well as menthol-based creams, dietary changes, meditation or hypnosis, and avoiding any known triggers (including allergens).

If you get significant hives over a large portion of your body and they come on quickly, you should seek medical treatment. Hives can be indicative of anaphylaxis, the most serious and severe form of allergic reaction, especially if the hives come on quickly and are all over the body.