constituting or forming a large number; numerous: many people. noting each one of a large number (usually followed by a or an): For many a day it rained. a large or considerable number of persons or things: A good many of the beggars were blind. the many, the greater part of humankind. many persons or things: Many of the beggars were blind.
Hives and angioedema can be caused by: 1  Foods. Many foods can trigger reactions in people with sensitivities. 2  Medications. Almost any medication may cause hives or angioedema. 3  Common allergens. Other substances that can cause hives and angioedema include pollen, animal dander, latex and insect stings.  Environmental factors.
Causes of Hives in Adults. Hives, also called urticaria, appear as itchy, red welts on the surface of the skin and are usually caused by an allergic reaction. Hives in adults start suddenly and go away quickly, can vary in size, appear anywhere on the body, and can move around on the body throughout the course of the reaction. Allergic Reaction.