What is arm weakness (unilateral)?
A person with unilateral arm weakness has muscle weakness in one arm. 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 arm.

What are the symptoms of arm weakness (unilateral)?
Symptoms of arm weakness (unilateral) depend on underlying cause. Associated symptoms may include arm pain, arm swelling, and arm numbness (unilateral).

How does the doctor treat arm weakness (unilateral)?
Treatment for arm weakness (unilateral) depends on the underlying cause for the weakness.