Usually there are the following reasons will lead to sleeping on your back: 1, abnormal brain wave discharge, that is, the brain neuronal cortex can not be normal rest and dormancy, when there will be abnormal cortical discharge, for example, patients who have had epilepsy or Parkinson’s disease in the past, during sleep, there will be deep sleep phase difficulties, shallow sleep phase normal enhancement, at this time belongs to the brain nucleus abnormal discharge of the cause. 2, when sleeping Sleeping on your back, usually because of cerebrovascular ischemia and cerebrovascular insufficiency of blood supply, usually in the case of insufficient blood supply to the cerebral arteries, such as vertebral basilar artery ischemia or ischemia leading to transient spasms, when you can not sleep flat, take the sleeping position of sleeping on your back, can slightly alleviate the cerebrovascular spasm.