Question

immediately tell me ...about allergy....​

Answer 1

An allergy is an immune system response to a foreign substance that's not typically harmful to your body. These foreign substances are called allergens. They can include certain foods, pollen, or pet dander. Your immune system's job is to keep you healthy by fighting harmful pathogens.

Answer 2

Allergies are reactions which are brought about when the immune system reacts to foreign substances in the environment. Autoimmunity is a system of responses from the immune system against the body's healthy cells and tissues.