What is the primary function of a decongestant?

The primary function of a decongestant is to relieve congestion. Decongestants work by narrowing the blood vessels in the nasal passages, which reduces swelling and congestion, making it easier to breathe. They are commonly used to treat conditions such as allergies, colds, or sinus infections, where nasal congestion is a significant symptom. By alleviating this symptom, decongestants help improve airflow and provide relief from the feeling of pressure in the sinuses and nasal cavities.

The other options pertain to different types of medications with distinct functions. Inducing sleep relates to sedatives or sleeping pills, suppressing cough refers to antitussives, and replacing hormones involves hormone replacement therapy. Each of these serves a unique purpose that does not align with the primary aim of decongestants.