What is the main purpose of antihistamines?

Antihistamines primarily serve the purpose of alleviating allergies. They work by blocking the action of histamine, a substance in the body that is released during allergic reactions. Histamine is responsible for symptoms such as itching, sneezing, runny nose, and hives, which are common in conditions like hay fever or other allergic responses. By inhibiting histamine's action, antihistamines effectively reduce these uncomfortable symptoms, providing relief for individuals suffering from allergies.

Other options, while related to different medical conditions, do not align with the primary function of antihistamines. For example, reducing blood pressure is typically the role of antihypertensive medications, treating infections would require antibiotics or antiviral medications depending on the pathogen, and anxiety is often managed with anxiolytics or antidepressants, not antihistamines. Thus, while each choice addresses a significant health concern, only the one focusing on alleviating allergies directly corresponds to the main purpose of antihistamines.