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.
Chronic urticaria and angioedema: Hives lasting more than six weeks. The cause of this type of hives is usually more difficult to identify than those causing acute urticaria. For most people with chronic urticaria, the cause is impossible to determine. In some cases, though, the cause may be thyroid disease, hepatitis, infection, or cancer.