Thoracic outlet syndrome includes those disorders that result in compression of nerves or blood vessels supplying the arms.
The thoracic outlet is the area of the body between the collarbone and the rib cage. Veins, nerves, and arteries come through this opening. When the blood vessels or nerves are compressed or squeezed, the pressure causes the symptoms of thoracic outlet syndrome.
Causes of thoracic outlet may include:
Sometimes a cause cannot be identified.