Numbness in the little finger while sleeping is caused by the following points: 1. It may be caused by a posture that compresses local nerves while sleeping and generally does not require special treatment. The patient’s symptoms will not last too long and can be relieved after appropriate activities.2. It may also be caused if the patient has cervical spondylosis, and there may also be soreness and discomfort in the neck muscles. The diagnosis can be clarified by performing cervical spine nuclear magnetic examination, and cervical spondylosis should be actively treated, and some nerve-nourishing drugs can be applied if necessary. 3. If the patient has a small cerebral infarction or a small amount of cerebral hemorrhage, it may also cause acute onset, which is more common in middle-aged and elderly people. Cranial CT and cranial MRI should be checked to clarify the diagnosis and hospitalization after the onset.