Snoring is caused by the vibration of the soft parts of your throat in a restricted airway. There are three major factors that lead to snoring. These include a constricted airway, loose muscles in the airway, or fluids in the airway. A constricted airway is often caused by an enlarged uvula (the piece of tissue that hangs from the back of the throat), large tonsils, or oversized adenoids. Other inflamed or swollen tissue may be the blame in times of illness. Loose muscles in the airway can often be caused by such things as alcohol, drugs or sedatives. Being overweight and out of shape can also be a factor. Fluids in the airway, often caused by allergies or excess nasal secretions can also cause snoring.