One of my college roommates had bad allergies. He sneezed a lot, but his biggest issue seemed to be a constantly stuffy nose. He was never without a bottle of Neo-Synephrine (phenylephrine) nearby. He often awoke during the night for a "hit". I felt sorry for him - and was often annoyed about his almost constant use of that spray bottle. It wasn’t until years later that I learned how the drug in the spray was actually the problem.
My roommate was suffering from rebound congestion.
Rebound congestion is the result of abnormal swelling and enlargement (hypertrophy) of the nasal mucosa, which blocks the nasal airway completely and causes extreme discomfort. This rebound congestion is temporarily relieved once again by another dose of nasal spray. The longer the spray is used, the shorter the intervals between additional sprays. In a short time, the drug being used to relieve stuffiness is actually causing it.
In my example, the use of the spray had become an addiction and a necessary part of that person's life. I sometimes wonder if my old roommate ever discovered the true cause of his problem and stopped using the decongestant spray.
My friend wasn't alone. There were many people back then who had not heard about rebound congestion. Some who did, reasoned that using a tiny, pediatric dose was safer than the full strength version. The fact is that even tiny doses can initiate the swelling. The problem persists to this day.
Phenylephrine is still available and there are other products as well. It is well know that Afrin (Oxymetazoline nasal spray) causes rebound congestion, yet millions of people use it regularly. Some people are as addicted as my roommate was. Whether they know it or not, they are endangering their health by using those drugs.
Nasal stuffiness can be controlled without drugs.