IMMUNOLOGY

Detailed explanation-1: -If you are born with certain genes, your immune system may react to substances in the environment that are normally harmless. These substances are called allergens. Having an allergic reaction is the most common example of an overactive immune system. Dust, mold, pollen, and foods are examples of allergens.

Detailed explanation-2: -Anaphylaxis is the result of your body’s immune system overreacting to a harmless substance, such as food. Substances that trigger allergic reactions are known as allergens. Anaphylaxis usually develops within minutes of contact with an allergen, but sometimes the reaction can happen up to 4 hours later.

Detailed explanation-3: -Allergic reactions start in your immune system. If you are allergic to a substance such as dust, mold, or pollen and you come into contact with it, your immune system may overreact. It may make antibodies that attack the substance. Something that causes an allergic reaction is called an allergen.

Detailed explanation-4: -Autoimmune disease is caused by an overactive immune system that attacks normal cells when there is no harmful foreign organisms present. Many factors can cause autoimmune disease, and the symptoms can diminish or get worse, they come and go over a lifetime.