Arm Weakness

Arms | Rheumatology | Arm Weakness (Symptom)


Arm weakness is a condition characterized by the loss of strength in the arm. Weakness in the arms can appear on one or both sides of the body, can come along with weakness in other parts of the body, and may occur with other symptoms such as arm pain.


Usual causes of arm weakness include injury to, or infection of, the arm; muscle wasting, such as from certain muscular disorders or from lack of use; nerve damage or compression at the vertebral column; or certain hereditary conditions. Stroke is a serious and potentially life-threatening cause of sudden arm weakness that appears on one side of the body. Temporary arm weakness may be caused by a general infection, such as the common cold.

Symptoms depend on underlying cause for the arm weakness. Associated symptoms may include muscles aches, fever, and arm numbness (bilateral). A person with bilateral arm weakness has muscle weakness in both arms. Weakness can be caused by malfunction of part of the brain, spinal cord, or spinal nerves. All of these structures play a role in stimulating the muscles to move the arms.

Diagnosis and Treatment

With arm weakness, difficulty in simply moving the affected arm, or difficulty performing daily tasks can occur. In some cases, physical therapy may help to improve arm strength. If arm weakness occurs with pain, pain medication may assist in resolving both symptoms. Optimal treatment for arm weakness is dependent on the underlying cause of the weakness.