Allergic Reaction

An allergic reaction occurs when the immune system mistakenly identifies a normally harmless substance—such as pollen, food, or pet dander—as a threat. In response, the immune system releases chemicals like histamine, leading to symptoms like sneezing, itching, swelling, or difficulty breathing. These reactions can range from mild to severe, sometimes causing life-threatening conditions like anaphylaxis. Allergic reactions are caused by an overactive immune response, and management often involves avoiding triggers and using medications like antihistamines or epinephrine in emergencies.