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.
Other than stress, the causes of chronic hives are quite different when compared to the causes of acute hives. Allergies only cause about 5 to 10% of chronic hives cases. When allergies cause chronic hives, pet allergy is usually to blame. Pollen, mold or dust mite allergies only rarely cause chronic hives. Chronic infections, such as viral hepatitis, sinus infections, and urinary tract infections, can cause chronic hives. Some studies have shown that infection with Helicobacter pylori, a bacteria commonly connected with stomach ulcers, is also associated with chronic hives.