The muscles on the arm always jump consider muscle strain, cold, neuropathy and other reasons. 1. muscle strain: due to exertion or a posture caused by too long a muscle spasm, so there will be jumping, in the local massage, relax the local muscle symptoms can be reduced. 2. Cold: The local blood circulation is not good after catching a cold, which causes muscle spasm, and the symptoms can be alleviated by applying hot compresses. 3. Neuropathy: such as polyneuritis, herniated intervertebral disc compression of the nerve, multiple sclerosis and other causes of muscle not innervated by the nerves appear to jump. The application of nutritive neurological drugs such as methylcobalamin may reduce. There are many reasons why the muscles on the arm are always jumping, and you need to go to the hospital for further examination and treatment after clarifying the cause.