Allergies happen when your body's immune system overreacts to harmless substances in the environment, called allergens. These allergens can be found in dust mites, pets, pollen, insects, ticks, molds, foods, and medications.
Normally, the immune system recognizes and fights off harmful invaders like bacteria and viruses. However, in people with allergies, the immune system mistakenly identifies these harmless allergens as threats. This triggers a chain reaction that releases chemicals like histamine, leading to allergy symptoms.
Here's a breakdown of how allergies develop:
- Exposure to allergens: Allergens can be inhaled, ingested, or enter through the skin.
- Immune system sensitization: The first exposure to an allergen may not cause symptoms. However, it sensitizes the immune system.
- Antibody production: The immune system produces antibodies, specifically immunoglobulin E (IgE), against the allergen.
- Mast cell activation: When a sensitized person is re-exposed to the allergen, IgE antibodies bind to mast cells.
- Histamine release: The binding triggers mast cells to release histamine and other chemicals, leading to allergy symptoms.
These symptoms can range from mild to severe, depending on the allergen and the individual's sensitivity. Common allergic reactions include sneezing, coughing, runny nose, watery eyes, skin rashes, hives, and even anaphylaxis, a life-threatening allergic reaction.
