The main causes of sinus problems are allergies, blockages, narrow or extra sinuses and a deviated nasal septum, according to WebMD. Some sinus problems are caused by swollen tissues in the nose, which can result from a cold, the environment or allergies.
Sinus blockages occur when the opening that allows sinus drainage gets blocked or bottlenecked, causing mucus to back up, notes WebMD. Approximately 10 percent of people have an extra sinus, which narrows the drainage opening. This extra sinus may cause sinus problems. Roughly 80 percent of people have a deviated nasal septum, which occurs when the bone and cartilage wall that separates the nostrils is displaced due to physical trauma or genetics. This causes one nostril to be smaller than the other, which can result in sinus issues.
Some people have narrow sinus passages from genetics, which can lead to sinus problems, states WebMD. Others are sensitive to environmental factors that may cause the blood vessels in the nose to dilate. Environmental conditions and allergens can also cause chemicals in the nose to be released, leading to swelling. Strong chemical odors, tobacco and other irritants can cause sinus problems. Some sinus problems may require a prescription medication. If sinus problems are persistent, surgery may be necessary.