Thoracic Outlet Syndrome

Thoracic outlet syndrome is a set of symptoms in the shoulder, arm or hand that occurs from a narrowing of the thoracic outlet (the space between the collarbone and first rib). Thoracic outlet syndrome is not common and can affect people of any age.

Shoulder muscles normally keep the collarbone or clavicle elevated and in place. With thoracic outlet syndrome, the upper rib and clavicle are closer, which makes the thoracic outlet smaller. Nerves and blood vessels in the area may be compressed.


  • Repetitive overhead arm movements 
  • Having an extra rib at birth
  • Bulky shoulder and neck muscles (due to weight training or swimming)
  • An abnormality in the neck muscles at birth
  • Neck injury
  • Injury to the first rib or collarbone
  • Poor posture 
  • Obesity


Symptoms may come and go, depending partially on activity level. Overhead activities may exacerbate symptoms. While symptoms typically occur on only one side, they may affect both sides of the body.

  • Aching in the neck, shoulder, arm or hand
  • Pain, numbness, or tingling in the forearm or fingers
  • Hand weakness
  • Limited range of arm motion
  • A depression in the shoulder
  • Neck pain
  • Swelling and redness of the arm
  • Pale and cool arm or hand

Diagnosing Thoracic Outlet Syndrome

Thoracic outlet syndrome is often more difficult to diagnose than other shoulder problems.

  • Physical exam: evaluates whether certain hand and arm movements trigger symptoms 
  • Nerve conduction tests: evaluates how nerves are affected
  • Doppler ultrasound: examines blood flow through arm and hand
  • Chest X-ray: checks for abnormal bone, such as an extra rib
  • CT scan: provides a more detailed look than an X-ray
  • CT angiography: gathers more information about blood flow through the arm
  • MRI: creates a detailed view of your body when posed in different positions (with arms at your side and overhead)


  • Physical therapy to help strengthen shoulder muscles, improve posture and enlarge the thoracic outlet space
  • Over-the-counter pain medications to relieve pain and swelling, and encourage muscle relaxation
  • Clot-dissolving mediations
  • Weight loss, if needed
  • Modification of everyday activities that bring on symptoms

These treatments relieve symptoms for most people. If significant symptoms persist, surgery may be an option. For instance, an extra rib (if present) may be removed. A doctor may release an abnormal muscle in the neck or perform surgery on the blood vessels in the neck. The exact kind of surgery depends on the anatomy of the thoracic outlet.