@explainique: Ever wonder why allergies make you sneeze, itch, or develop watery eyes? It all comes down to histamine — a chemical released by the immune system during an allergic reaction. Antihistamines work by blocking histamine signals at H1 receptors, helping calm symptoms like sneezing, runny nose, itchy eyes, and hives. Older antihistamines may cause more drowsiness, while newer options are usually less sedating. #Antihistamines #Allergies #Histamine #Pharmacology #HealthcareEducation