1. **Allergens:** Allergies are triggered by allergens, which are substances that can cause an allergic reaction. Common allergens include pollen, dust mites, pet dander, certain foods (e.g., nuts, shellfish, milk), insect stings, and latex.

2. **Immune System Response:** When a person with allergies comes into contact with an allergen, their immune system reacts by producing antibodies called immunoglobulin E (IgE). These antibodies trigger the release of histamines and other chemicals, leading to allergy symptoms.

3. **Types of Allergies:** There are various types of allergies, including:
– **Environmental Allergies:** These are triggered by substances in the environment, such as pollen, dust, mold, and pet dander.
– **Food Allergies:** These are reactions to specific foods and can range from mild to severe. Common food allergens include peanuts, tree nuts, eggs, and dairy products.
– **Insect Allergies:** Some people are allergic to insect stings or bites, particularly from bees, wasps, and ants.
– **Drug Allergies:** Certain medications can cause allergic reactions in some individuals.
– **Latex Allergy:** Latex, found in rubber gloves and medical equipment, can trigger allergic reactions in sensitive individuals.

4. **Symptoms:** Allergic reactions can vary widely in severity. Common allergy symptoms include:
– Sneezing
– Runny or stuffy nose
– Itchy or watery eyes
– Skin rashes or hives
– Swelling (angioedema)
– Coughing and wheezing
– Gastrointestinal symptoms (nausea, diarrhea) in food allergies
– Anaphylaxis, a severe and potentially life-threatening reaction that requires immediate medical attention

5. **Diagnosis:** Healthcare professionals diagnose allergies through a combination of medical history, physical examination, and allergy testing. Allergy tests may include skin prick tests, blood tests for specific IgE antibodies, and oral food challenges.

6. **Management:** Managing allergies typically involves allergen avoidance, medication to alleviate symptoms (antihistamines, decongestants), and, in some cases, allergen immunotherapy (allergy shots) to desensitize the immune system. Individuals with severe allergies may carry epinephrine auto-injectors to treat anaphylactic reactions.

7. **Prevention:** Preventing allergic reactions involves identifying and avoiding allergens whenever possible. This may include lifestyle modifications, such as using air purifiers, practicing good hygiene, and reading food labels carefully.

8. **Ongoing Research:** Allergy research continues to advance our understanding of the causes and treatments for allergies. Ongoing studies explore genetic factors, the role of the microbiome, and new therapeutic options.