Allergic disorders occur when the immune system overreacts to substances known as allergens, which can include pollen, dust mites, pet dander, and certain foods. This overreaction can lead to symptoms such as sneezing, itching, rashes, and difficulty breathing. Common allergic disorders include hay fever, asthma, and eczema. These conditions can vary in severity and may affect individuals differently. Diagnosis typically involves a medical history review and allergy testing. Treatment options often include avoiding allergens, using medications like antihistamines, and in some cases, undergoing immunotherapy to reduce sensitivity to specific allergens.