Some people do not know the difference between snoring and sleep apnea. The human body is designed in many different variations. Overweight people tend to have more blocking tissues in the esophagus which constrict the air passageway. This condition of the passageway can also be experienced by someone who has a large uvula. There are also other reasons that can cause snoring like: oversized tonsils, a long tongue, large adenoids, a deviated nasal septum, and a tiny lower jaw. For these people, the possibility of having snoring problems is very much increased.
Things like cigarettes and asthma will also increase the likelihood of acquiring a snoring problem.
The way you position your body during the night is also a concern. When gravity pulls the tongue and jaw down to the back of the mouth due to sleeping on your back, the airway becomes smaller and therefore, can lead to snoring. Using devices like stop snoring mouthpieces can help.