Arm numbness is caused by poor blood flow to the end of the limb, the common causes are the following: 1, incorrect sleeping posture, incorrect sleeping posture compression of the nerve in the arm, resulting in inadequate blood supply to the end of the limb caused by hand numbness symptoms. 2, cervical spine disease, cervical spine disease can cause dizziness, neck discomfort, compression of the nerve caused by numbness of the fingers and other symptoms. 3, lipid abnormalities, night rest after the slowdown of basal metabolism, blood flow slows down This leads to insufficient blood supply to the end of the limbs causing hand numbness symptoms. Lipid abnormalities can cause cerebral atherosclerosis, causing cardiovascular diseases, such as coronary heart disease, cerebral infarction, etc.. If you have symptoms of neck discomfort, it is best to go to the hospital to check the cervical spine film to confirm the diagnosis, and further check the blood lipids, blood pressure, etc., to rule out dyslipidemia and other diseases first.