Numbness in the palm of the left arm when raising and lowering it for a while may be related to poor peripheral blood circulation, peripheral neuropathy, cervical spondylosis and so on. 1. Poor peripheral blood supply: People with poor peripheral blood circulation due to low body temperature and malnutrition may experience numbness when lifting their left arm. Symptoms can be relieved by local massage or soaking the hand in hot water. 2. Peripheral neuropathy: often due to neuroinflammation, decline or degeneration of nerve groups, the infected nerves are itchy and lose sensation. Peripheral nerve damage may cause numbness in the palm of the hand when the left arm is raised and lowered for a period of time. Some neurotrophic drugs such as methylcobalamin tablets and vitamin B1 can be taken as prescribed by the doctor. 3. Cervical spondylosis: herniated cervical intervertebral disc or cervical spondylolisthesis, leading to nerve compression, resulting in numbness in the palm of the hand when the left arm is lifted up and put down for a while. Commonly used pain relief, anti-inflammatory, nutritive drugs, such as oral diclofenac or flunarizine hydrochloride tablets, with vitamin B1 and other drugs. The above medicines are for reference only, and the specific dosage should follow the doctor’s prescription. When the left arm lifting a moment to put down the palm of the numbness, it is recommended to consult a doctor in a timely manner, in accordance with the doctor’s instructions for further examination, in the doctor’s help for targeted treatment.