Lower Back Issues

Thoracic Outlet Syndrome

Causes
The main cause of TOS is that the nerves and blood vessels going to the arm and hand get squeezed near the thoracic outlet. This can occur for many reasons.

Pressure on nerves and vessels can happen in people who have fractured their clavicle. It can also happen in people who have an extra first rib, although this doesn’t always result in TOS.

Extra muscle or scar tissues in the scalene muscles can put extra pressure on the nerves and arteries. Heavy lifting and carrying can bulk up the scalenus muscles to the point where the nerve and arteries get squeezed.

Traumatic injury from a car accident can also cause problems that lead to TOS. In an accident, the shoulder harness of the seat belt can strain or tear the muscles. As they heal, scar tissue can build up, putting pressure on the nerves and blood vessels at the thoracic outlet.

Neck and arm positions used at work and home may contribute to TOS. People who have to hold their neck and shoulders in awkward alignment sometimes develop TOS symptoms. TOS symptoms are also reported by people who have to hold their arms up or out for long periods of time.

People with TOS often slouch their shoulders, giving them a drooped appearance. The poor body alignment of slouching can compress the nerves and arteries near the thoracic outlet. Being overweight can cause problems with posture, and women who have very large breasts may also have a droopy posture. For some reason, TOS affects three times as many women as men.

Symptoms
TOS causes pain along the top of the clavicle and shoulder. The pain may spread along the inside edge of the arm. Occasionally pain spreads into the hand, mostly into the ring and pinky fingers. Numbness and tingling, called paresthesia, may accompany the pain, especially in the early hours of the morning before it’s time to wake up. Symptoms tend to get worse when driving, lifting, carrying, and writing. The arms may also feel tired when held overhead, as when using a blow dryer. It may be harder to hold and grip things, and the hand may feel clumsy.

Symptoms related to the blood vessels are less common. If the blood vessels are causing symptoms, the arm and shoulder may feel heavy and cold. The arm may become somewhat blue (cyanotic), and the constriction of vessels can cause the arm and hand to swell. Problems with the blood vessels that go to the arm are serious. If you experience these symptoms, you should call your doctor right away.

TOS symptoms are similar to the symptoms of many other conditions. A herniated disc in the neck, carpal tunnel syndrome in the hand, and bursitis of the shoulder can all cause symptoms very much like those of TOS.