The septum is the bone and cartilage which separates the two sides of the nose. A deviated septum is simply a crooked septum. A deviated septum commonly can cause or exacerbate chronic sinusitis by causing a blockage of the nose and also of the drainage area from the sinuses. Most people have a somewhat deviated septum. Just because your septum is deviated, it doesn't mean that it is causing a problem-but it does need to be evaluated. There are some patients who have such a severe deviated septum that they need to have surgery. That may need to be evaluated by an otolaryngologist or sinusitis specialist.
There is a device called the Breathe Right nasal strip which you may have seen athletes wear. It looks like a band-aid that goes across the nose but actually opens up the nose with a spring-like mechanism which is contained in the Breathe Right strip. Many patients with a deviated septum find that their nose will open up if they use it. Unless you're a football player, you will probably decide not to use it during the daytime, but since many patients have worsening of symptoms at night, it can be helpful when used then.