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.
This, in turn, can cause the weals to form on the surface of your skin. Hives can further be categorized by how long they last. Acute hives last for less than six weeks; chronic hives can last longer. In many cases, a trigger that causes acute hives is not the same as what causes chronic hives. Viral Infections The most common cause of acute hives, particularly in children, is a viral infection such as an upper respiratory infection.