The symptoms of numbness in one hand may be caused by compression of one side of the limb, peripheral neuropathy, cervical disc herniation, cerebrovascular disease and so on. 1. One side of the limb is compressed: if you keep lying on your side for a long time, looking down at the cell phone, etc., because one side of the limb is compressed for a long time, causing the blood circulation of the hand to be impaired, which may lead to the nerve of the upper limb is compressed, and the phenomenon of numbness occurs. 2. Peripheral neuropathy: peripheral neuropathy is relative to central neuropathy, a history of diabetes or exposure to heavy metals belongs to peripheral neuropathy, can appear a hand numbness. 3. Cervical disc herniation: because the nerve root is compressed, resulting in the nerve of the hand is affected, there will be numbness in the hand, can be diagnosed through the cervical spine three-dimensional film or magnetic resonance imaging and other tests. 4. Cerebrovascular disease: cerebral thrombosis or cerebral hemorrhage and other brain diseases, the central nervous system will be damaged, the innervated hand sensation will be abnormal, which will produce symptoms of hand numbness. The symptoms of numbness in one hand may also be carpal tunnel syndrome, elbow syndrome, and it is recommended that patients go to the hospital in time to find out the cause of the symptomatic treatment.