A decongestant, or nasal decongestant, is a type of pharmaceutical drug that is used to relieve nasal congestion in the upper respiratory tract. The active ingredient in most decongestants is either pseudoephedrine or phenylephrine.

What do decongestants do?

Decongestants are a type of medicine that can provide short-term relief for a blocked or stuffy nose (nasal congestion). They can help ease the symptoms of conditions such as colds and flu, hay fever and other allergic reactions, catarrh and sinusitis.

What does decongestant mean in medical terms?

: an agent that relieves congestion (as of mucous membranes) decongestant. adjective. Medical Definition of decongestant (Entry 2 of 2) : relieving or tending to relieve congestion nasal decongestant action.