Thoracic Outlet Syndrome

Thoracic outlet syndrome (TOS) is a set of generalized symptoms characterized by pain in the arms and upper body caused by nerve or blood vessel compression. The thoracic outlet is the area connecting the neck to the chest. This area is a major thoroughfare for the body: the esophagus, trachea, several major blood vessels and many nerves pass through the thoracic outlet.

Thoracic outlet syndrome may occur if nerves or blood vessels become trapped between ribs and muscles.

Risk Factors for Thoracic Outlet Syndrome

Pain from thoracic outlet syndrome occurs most often in women aged 35 to 55. Women comprise 75 percent of thoracic outlet syndrome patients.

The causes of thoracic outlet syndrome may include birth defects, trauma, poor posture, obesity and heavy exercise. In most cases, however, the cause of thoracic outlet syndrome is unknown.

Thoracic Outlet SyndromeThoracic Outlet Syndrome Pain and Other Symptoms

Pain in the hands, arms and shoulders is the primary symptom of thoracic outlet syndrome. The pain is most often felt down the inside of the arms, but occasionally pain radiates down the sides of the body. Thoracic outlet syndrome also causes paraesthias, or pins and needles.

If the subclavian artery is compressed, symptoms may include bluish skin (cyanosis) due to restricted blood circulation and swelling in the hands, arms and shoulders. Cases of very severe thoracic outlet syndrome may result in Raynaud’s syndrome, a blood circulation disorder of the hands that is triggered by cold or stress.

Exceptionally severe thoracic outlet syndrome may restrict blood circulation so thoroughly that gangrene develops in the fingers. Fortunately, symptoms severe enough to cause gangrene are rare.

Types of Thoracic Outlet Syndrome

TOS is classified into several categories.

Arterial Thoracic Outlet Syndrome: Arterial thoracic outlet syndrome is caused by a rare birth defect. The condition often develops at a young age and affects only one side of the body. Symptoms include pain, finger sores, cold intolerance, muscle weakness and fatigue.

Disputed Thoracic Outlet Syndrome: Disputed thoracic outlet syndrome is also called common thoracic outlet syndrome or nonspecific thoracic outlet syndrome. Disputed thoracic outlet syndrome describes patients with chronic thoracic pain and have other disease or syndrome. This means the underlying cause cannot be accurately determined.

Disputed thoracic outlet syndrome is thought to arise from trauma to the brachial plexus nerves. Symptoms include pain, fatigue and weakness.

Neurologic Thoracic Outlet Syndrome: A rare condition, neurologic thoracic outlet syndrome is caused by congenital defects. Pain may result from a cervical rib (a tiny extra rib in the neck) or from structural abnormalities in the subclavian arteries, the blood vessels found under the collarbone.

Neurologic thoracic outlet syndrome usually affects only one arm and it affects women more than men. Symptoms include cold intolerance, numbness in the hand and weak hand muscles.

Traumatic Thoracic Outlet Syndrome: As the name implies, traumatic thoracic outlet syndrome results from injury or from long-term repetitive actions. Musicians are at particular risk of traumatic TOS. Symptoms include pain, pins and needles, loss of sensation in the affected arm and muscle weakness.

Venous Thoracic Outlet Syndrome: Venous thoracic outlet syndrome is a rare condition that affects both genders equally. The exact cause is unknown, but pain usually develops after intense exercise.

Diagnosing Thoracic Outlet Syndrome

Diagnosis of thoracic outlet syndrome requires a detailed medical history, the patient’s description of pain and other symptoms and a physical examination. No single diagnostic test can prove the presence of TOS. A stethoscope may detect bruits or unusual blood vessel noises in the thoracic outlet if blood vessels are compressed.

Angiopathy, an x-ray taken after injecting contrast dye into the blood, may detect abnormal blood flow in affected arms. Diagnosis may also be aided by electromyography, a nerve test that can reveal neuromuscular abnormalities.

Treating TOS Pain

If thoracic outlet syndrome derives from a physical abnormality, as in the case of neurologic thoracic outlet syndrome, surgical solutions are possible. Surgery can remove clavical ribs or subclavian artery blockages. However, as pain and other symptoms often persist even after corrective surgery, many doctors are unwilling to suggest a surgical solution.

Non-steroidal anti-inflammatory drugs (NSAIDs) may be used to relieve pain. Improving posture may alleviate pain by relieving pressure on compressed nerves or blood vessels. Physical therapy designed to build the shoulder muscles may also relieve some pain.

Lifestyle changes are often recommended for thoracic outlet syndrome treatment. Losing weight can relieve pressure. Avoiding tasks that exacerbate pain is often recommended. Paying attention to office ergonomics may also reduce thoracic outlet syndrome pain.

Preventing Thoracic Outlet Syndrome Pain

According to the American Academy of Orthopedic Surgeons, people with TOS can take certain measures to help minimize their symptoms, such as avoiding carrying heavy bags on the affected shoulder and performing specific exercises.

Exercises recommended by the AAOS to help prevent TOS associated pain should be done twice daily and include the following:

Neck Stretch: Put one hand behind your back and the other over your head. Gently pull your head towards the shoulder until you can feel a stretch. Hold five seconds. Repeat on the other side. Stretch each side ten times.

Shoulder Shrug: Shrug your shoulders to maximum height. Then roll backwards and down to resting position. Repeat ten times.

Neck Retraction: Keeping your jaw level and your back straight move your head backwards. Hold five seconds. Repeat ten times.

Corner Stretch: Facing an empty corner spread your arms out to shoulder height. Walk towards the wall until you can place your hands flat, one on each wall. Gently lean into the corner to stretch the muscles in your chest. Hold for five seconds. Repeat ten times.

If you feel any pain, stop.


American Academy of Orthopaedic Surgeons. (2000, September). Thoracic outlet syndrome.

Beers, M.H.