Sleeping and snoring loudly can be caused by bad living habits, nasal diseases, pharyngeal diseases, systemic diseases and other factors. 1. Bad living habits: such as daily study, work pressure, body overwork, or long-term smoking, drinking alcohol, can be snoring loudly during sleep. 2. Nasal diseases: when there are nasal polyps, deviated nasal septum, enlarged nasal turbinates and chronic rhinitis, etc., it can cause nasal blockage and narrowing of nasal passages, which can lead to loud snoring. 3. Pharyngeal diseases: Adenoid hypertrophy and tonsillar hypertrophy and other pharyngeal diseases can cause poor breathing, and snoring sound performance can occur due to the obstruction of breathing during sleep. 4. Systemic diseases: excessive obesity, diabetes, hypothyroidism and pregnancy, etc., can snore loudly while sleeping. When sleep snoring sound, should promptly seek medical treatment.