Thoracic outlet syndrome is a combination of pain in the neck and shoulder, numbness and tingling of the fingers, and a weak grip. The thoracic outlet is the area between the rib cage and collar bone.

Thoracic outlet syndrome is a rare condition.

Blood vessels and nerves coming from the spine or major blood vessels of the body pass through a narrow space near the shoulder and armpit on their way to the arms. As they pass by or through the collarbone (clavicle) and upper ribs, they may not have enough space. Pressure (compression) on these blood vessels or nerves can cause symptoms in the arms or hands. Problems with the nerves account for almost all cases of thoracic outlet syndrome.

Compression can be caused by an extra cervical rib (above the first rib) or an abnormal tight fibrous band connecting the spinal vertebra to the rib. Patients often have a history of injury to the area or overuse of the shoulder.

People with long necks and droopy shoulders may be more likely to develop this condition because of extra pressure on their nerves and blood vessels.