The causes of arm pain at night are as follows: 1, prolonged lying on one side, causing compression of the vascular nerve of one limb, resulting in the symptoms of arm pain; 2, overexertion, such as the usual lack of necessary physical exercise, suddenly carry out some heavy physical labor, it may cause the accumulation of lactic acid in the arm muscles, there will be symptoms of arm pain; 3, strenuous activity may The symptoms of arm pain may occur due to injury to the muscles, ligaments or joints of the upper limbs; 4. Degenerative joint disease or long-term strain may lead to epicondylitis of the humerus, and the symptoms of arm and elbow pain may also occur. It is necessary to pay attention to rest, avoid strain, pay attention to cold and warmth, avoid getting cold, and also need symptomatic treatment with anti-inflammatory and pain-relieving drugs to relieve the symptoms of pain.