1. Sleeping posture
When you sleep on your back, the weight of your neck or your chest presses down, and your airway collapses, blocking the airflow when you breathe, resulting in snoring.
2. Lifestyle and Habits
Being overweight or excessively smoking and consuming alcohol would narrow your throat and decrease the muscle tone, causing more vibration inside as you breathe, producing the snoring sounds.
3. Allergies and diseases
Having allergies like sinus or other nasal problems may cause your airway to be blocked, thereby resulting in more vibration and creating snoring sounds. In a worse condition, you might be having obstructive sleep apnea (OSA), a condition that blocks the throat and literally stops you from breathing while you're asleep.