To understand rebound congestion, you first need to understand how congestion occurs. Many people think that congestion is caused by mucus that blocks the nasal passages. This is only partially true.
The underlying cause lies in the blood vessels that line the nose. Certain conditions can cause these vessels to become swollen (get larger) or constrict (get smaller). When the vessels become swollen due to a cold virus, allergies, sinusitis, or any of a number of reasons, congestion occurs. When the vessels constrict, however, there is more space in the airways and symptoms subside. So medications used to treat congestion cause the nasal blood vessels to constrict.
The reasons why rebound congestion occurs are complicated and not well understood. What doctors and scientists do know is that within as little as three days after taking a nasal decongestant (such as oxymetazoline, pseudoephedrine, or phenylephrine), people may again experience severe congestion, which is only relieved by additional use of the nasal decongestant. Thus, a vicious cycle is set up. Some people may also have headaches, anxiety, and restlessness.
Rebound congestion can also be called rhinitis medicamentosa (RM), and some people will refer to this as an addiction to nasal sprays. Rebound congestion can be difficult to cure, which is why it is so important to use these nasal sprays sparingly and exactly as the label indicates.
Treatment for Rebound Congestion
If you are already addicted to a nasal spray, talk to your doctor. Some doctors may recommend a gradual decrease in the use of the medication until you are completely weaned off it. This may be preferable than trying to quit the medication outright, which may result in severe congestion for a number of days.
There is also a medication called Rhinostat that may be useful in easing this process. Rhinostat is essentially the same medication you're addicted to, but is dispensed in a manner that very carefully controls the dosage.
Division of Allergy & Clinical Immunology. Rhinitis Medicamentosa. Accessed: April 25, 2010 from http://www.jiaci.org/issues/vol16issue03/1.pdf
The Ear Nose and Throat Center. Nasal Congestion. Accessed: April 25, 2010 from http://www.entcenter.net/id149.htm