Many snoring sufferers know the source of their problem is right in front of their face -- their nose.  They cannot breathe freely because their nasal airways are blocked.  So they either laboriously nose-breathe at night, or they mouth-breathe, causing their throat tissues to vibrate.  Either way, the result is noisy snoring.

Various sprays, nose drops and pills can reduce nasal congestion, but for some people, the root cause is a deviated nasal septum. The nasal septum is the wall dividing the nasal cavity into halves; the front portion of this natural partition is made of firm but bendable cartilage covered by skin that has a substantial supply of blood vessels. The ideal nasal septum is exactly midline, separating the left and right sides of the nose into passageways of equal size.

Most of us have nasal septums that are off-center, a condition that generally causes no problem. A "deviated septum" occurs when the septum is severely shifted away from the midline. The most common symptom from a badly deviated or crooked septum is difficulty breathing through the nose. In some cases the crooked septum can interfere with the drainage of the sinuses, resulting in repeated sinus infections -- and, of course, loud snoring.

That needs to be addressed by surgery, known as septoplasty.  As described in this article, your doctor will first establish the site of the sinus blockage, then perform microsurgery to remove the blockage and reconstruct your nasal passages.

Another cause of snoring may be nasal polyps, soft, noncancerous (benign) growths that develop on the lining of your nose or sinuses. Small polyps can be treated with a corticosteroid nasal spray.  Larger polyps may require removal by Endoscopic sinus surgery.  (Source: MayoClinic.com)