Most Common Allergies

There are many different types of allergies. Some individuals have food allergies, and allergies involving animals and animal products, such as wool, are also common. Some individuals are allergic to substances floating in the air, such as pollen from certain flowers. This type of allergy is often colloquially referred to as hay fever, even though it has nothing to do with hay or fever. Symptoms of allergies are caused by histamines, which are substances released by the body in response to an allergen.