Rebound congestion is a constant nasal stuffiness (congestion) that develops from the overuse of decongestant medicine sprays. This type of congestion occurs even when a person is not experiencing allergies or other coldlike symptoms.

Rebound congestion can develop from using nasal decongestant sprays frequently for 3 or more days. As decongestant sprays wear off, sinus membranes swell, causing congestion, and a person may respond by using a higher dose of decongestant. If the cycle continues, a person builds up a tolerance by using larger and larger doses until congestion occurs whenever the person does not take the medication.

Rebound congestion can lead to addiction to decongestant nasal sprays.