Snoring is caused by the vibration of relaxed tissues in the throat and airway as air flows past them during breathing while asleep. Several factors contribute to this condition:

• When muscles of the soft palate, tongue, and throat relax during sleep, especially moving from light to deep sleep, tissues can sag and narrow the airway. This narrowing causes the tissues to vibrate with the airflow, creating the snoring sound.
• Anatomy plays a key role. For example, a low, thick soft palate, an elongated uvula (the tissue hanging at the back of the throat), a small chin, short neck, or excess tissues in overweight individuals can narrow the airway and increase snoring.
• Lifestyle factors such as alcohol consumption before bedtime relax throat muscles, reducing natural defenses against airway obstruction.
• Nasal issues like chronic congestion, allergic rhinitis, a deviated nasal septum, nasal valve collapse, or nasal polyps can obstruct airflow and contribute to snoring.
• Sleep position affects snoring. It's usually worse when sleeping on the back because gravity causes the tongue to fall backward, further narrowing the airway.
• Other causes include sleep deprivation, which increases throat muscle relaxation, obesity which adds extra tissue around the throat, and aging, which reduces muscle tone.
• Snoring can also be linked to health conditions like obstructive sleep apnea, hypothyroidism, and cardiovascular disease.

In summary, snoring is caused by any factor that narrows or obstructs the airway and leads to vibration of throat tissues as air flows past during sleep. This can include anatomical features, lifestyle habits, nasal problems, and underlying health conditions. Adjusting lifestyle factors and addressing nasal or anatomical issues can help reduce snoring. Severe snoring may indicate obstructive sleep apnea, which requires medical attention. This explanation reflects comprehensive causes of snoring based on medical sources. If you want, I can also provide information on how to reduce or treat snoring.