What are Allergies and Its Symptoms
An allergy is a heightened sensitivity to a foreign substance (called an allergen) that causes the body’s defense system (the immune system) to overreact when defending itself.
Normally, the immune system would only react if a harmful substance, such as bacteria, attacks the body. For people with allergies, their immune systems are working too hard and react even when relatively harmless substances, such as pollen, are present. The severity of an allergic reaction can vary from mild discomfort to life threatening situations.
Allergens can stimulate an immune response when you breathe in or touch the allergen, or by ingestion of food or beverage, or from injections of medication.
Common allergies include eczema, hives, hay fever, and asthma. You can get an allergic reactions from food, pet dander, airborne pollen, and the venom of stinging insects, such as wasps and bees. Treatments for allergies include avoidance, use of anti-histamines, steroids or other medications, and immunotherapy to desensitize the allergic response.