Pseudoephedrine is a nasal decongestant that can provide temporary relief from a stuffy nose. Sudafed is a common brand name. It eases congestion by reducing swelling in your nasal cavities. People with high blood pressure, heart disease and certain other medical conditions should talk to a healthcare provider before taking this medication.

The main active ingredient in Sudafed is called pseudoephedrine (PSE). It’s a nasal decongestant. PSE relieves congestion by making the blood vessels in your nasal passages narrower. This opens up your nasal passages and allows your sinuses to drain. As a result, your nasal passages are clearer and you breathe more easily.