Lying down at night and sleeping with stuffed nostrils may be related to chronic simple rhinitis, soft palate falling back, posterior nostril polyps, gravity factors and other reasons. 1. Chronic simple rhinitis: a common nasal disease, chronic inflammation of the mucous membrane of the nasal cavity and submucosal tissues can cause intermittent alternating nasal congestion, which is alleviated during the day or after activities, and aggravated by sedentary activities at night, and can lead to congestion of the nostrils at night when you lie down to sleep. 2. Soft palate falling back: For example, viral infection, pharyngitis, trauma and other factors may lead to soft palate falling back, which can also cause the nostrils to be stuffed up when you lie down to sleep at night. 3. Posterior nostril polyp: a type of nasal polyp, with the growth and development of the lesion tissue, when the swelling hangs over the posterior nostril, it will also cause the nostrils to be stuffed when you lie down to sleep at night. 4. Gravity factors: due to changes in body posture and position, gravity factors may also lead to stagnation of blood circulation in the nasal cavity and hypertrophy of the posterior segment of the inferior turbinate, resulting in stuffy nostrils when lying down to sleep at night. There may be other reasons why your nostrils are stuffed up when you lie down to sleep at night, so you need to go to the hospital for examination, clarify the cause of the problem, and actively treat it.