Allergies are caused by our immune system overreacting to harmless substances called allergens. Symptoms range from mild to severe and include sneezing, itching, and difficulty breathing. Common allergens include pollen, animal dander, dust mites, certain foods, and medications. Although allergies cannot be cured, they can be managed with medication, avoidance of triggers, and immunotherapy. Seek medical attention if you experience persistent or severe symptoms to determine triggers and develop a treatment plan.