What is thoracic outlet syndrome?

What Is Thoracic Outlet Syndrome

What is thoracic outlet syndrome?

Thoracic outlet syndrome (TOS) is a group of disorders that occur when blood vessels or nerves in the space between your clavicle and your first rib (thoracic outlet) are compressed. This can cause shoulder and neck pain and numbness in your fingers.

Common causes of thoracic outlet syndrome include physical trauma from a car accident, repetitive injuries from job- or sports-related activities, certain anatomical defects (such as having an extra rib), and pregnancy. Sometimes doctors don’t know the cause of thoracic outlet syndrome.

Types of thoracic outlet syndrome

Neurogenic (neurological) thoracic outlet syndrome

Neurogenic TOS is characterized by compression of the brachial plexus, a network of nerves that run from your spinal cord to your upper limbs and control muscle movements and sensation in your shoulders, arms, and hands. Neurogenic TOS can result in tingling, weakness, and even mild skin color changes when you raise your arms overhead. This is the most common type of TOS in adults.

Venous thoracic outlet syndrome

Venous TOS happens when the vein that drains blood from the arm, the subclavian vein is compressed as it travels under the clavicle and through the thoracic outlet. This can cause swelling, and redness or make your arm feel heavy when you use it or raise it overhead. In extreme cases, venous TOS can cause clotting of the vein, resulting in significant swelling and persistent pain. This situation is called effort thrombosis, or Paget-Schroetter disease. This type of TOS often affects children.

Arterial thoracic outlet syndrome

Arterial TOS occurs when the muscles and bones surrounding the thoracic outlet rub against (impinge) the subclavian artery, the artery that supplies blood to the arm. This can result in loss of blood flow to the arm and make your arm feel cold and painful. Often this is temporary, happening only when your arm is raised. However, severe or long-term arterial TOS can damage the artery, cause clotting and require emergency medical attention. The rarest form, arterial TOS, requires surgery to decompress the thoracic outlet.

How serious is thoracic outlet syndrome?

With proper treatment, TOS is a manageable condition. Although many cases of thoracic outlet syndrome are not preventable, the condition is treatable. Treatment is important to prevent serious complications. If left untreated, TOS can cause complications, such as:

  • permanent nerve damage and other neurological complications
  • permanent arm swelling and pain, especially in patients with venous TOS
  • blood clots
  • pulmonary embolism is a life-threatening condition in which a blood clot travels to the lungs
  • gangrene, the death of tissue often caused by a loss of blood flow

What are the symptoms of thoracic outlet syndrome?

It’s possible to have a mix of the three different types of thoracic outlet syndrome, with multiple parts of the thoracic outlet being compressed. Thoracic outlet syndrome symptoms can vary depending on the type. When nerves are compressed, signs and symptoms of neurogenic

thoracic outlet syndrome includes:

  • Numbness or tingling in your arm or fingers
  • Pain or aches in your neck, shoulder, arm, or hand
  • Weakening grip

Signs and symptoms of venous thoracic outlet syndrome can include:

  • Discoloration of your hand (bluish color)
  • Arm pain and swelling
  • Blood clots in veins in the upper area of your body
  • Arm fatigue with activity
  • Paleness or abnormal color in one or more fingers or your hand
  • Throbbing lump near your collarbone

Signs and symptoms of arterial thoracic outlet syndrome can include:

  • Cold fingers, hands, or arms
  • Hand and arm pain
  • Lack of color (pallor) or bluish discoloration (cyanosis) in one or more of
    your fingers or your entire hand
  • Weak or no pulse in the affected arm

What causes thoracic outlet syndrome?

Thoracic outlet syndrome is usually caused by compression of the nerves or blood vessels in the thoracic outlet, just under your collarbone (clavicle). The cause of the compression varies and can include:

  • Anatomical defects. Inherited defects that are present at birth (congenital) may include an extra rib located above the first rib (cervical rib) or an abnormally tight fibrous band connecting your spine to your rib.
  • Poor posture. Drooping your shoulders or holding your head in a forward position can cause compression in the thoracic outlet area.
  • Trauma. a traumatic event, such as a car accident, can cause internal changes that then compress the nerves in the thoracic outlet. The onset of symptoms related to a traumatic accident often is delayed.

Risk factors

Several factors seem to increase the risk of thoracic outlet syndrome, including:

  • Sex. Females are greater than three times more likely to be diagnosed with thoracic outlet syndrome, then are males.
  • Age. Thoracic outlet syndrome may occur at any age, but is most commonly diagnosed in adults between the ages of 20 and 50.


If you’re at risk for thoracic outlet compression, avoid repetitive movements and lifting heavy objects. If you’re overweight, losing weight may help you prevent or relieve symptoms of thoracic outlet syndrome. Even if you don’t have symptoms of thoracic outlet syndrome, avoid carrying heavy bags over your shoulder, because this can increase pressure on the thoracic outlet.

Stretch daily, and perform exercises that keep your shoulder muscles strong. Daily stretches focusing on the chest, neck, and shoulders can help improve shoulder muscle strength and prevent thoracic outlet syndrome.

Diagnosis and Treatment


Proper diagnosis is the most important step in treating thoracic outlet syndrome. Your doctor will perform a complete physical exam and review the results of previous diagnostic tests. Your doctor may recommend a thorough evaluation by a skilled neurologist to rule out cervical spine disease and other neurological conditions with similar symptoms.

Additional tests that help diagnose thoracic outlet syndrome include:

  • nerve conduction studies to evaluate the function of the motor and sensory nerves
  • vascular ultrasound studies of the arteries or veins
  • chest X-ray to rule out cervical rib abnormalities
  • computed tomography (CT) scan or magnetic resonance imaging (MRI) of the chest or spine
  • magnetic resonance imaging with angiography (MRA) to view blood vessels
  • arteriogram/venogram, an X-ray that uses dye to look at blood flow

Proper diagnosis is the most important step in treating thoracic outlet syndrome. Your doctor will perform a complete physical exam and review the results of previous diagnostic tests.


Most cases of neurogenic thoracic outlet syndrome can be treated with physical therapy and medication. Severe cases may require surgery.

Rehab Modalities

Osteopathy, Chiropractic and physiotherapy can help to treat patients by applying Electro therapy, Manual therapy, and a variety of exercises that effectively stretch open the tissues of the thoracic outlet. These are done with and without weights to pull the outlet into a “relaxed” open position. Physical therapy may be done before surgery, as in the case of neurogenic TOS, or may be prescribed after surgery to help you regain strength and stability.


Your doctor might prescribe medications such as anti-inflammatory medications (ibuprofen, Advil) or muscle relaxants to help relieve your symptoms. Cortisone injected into a joint or muscle can help lower inflammation and provide relief. If you have venous or arterial TOS, your doctor may prescribe blood thinners to prevent or treat blood clots.


Although neurogenic TOS can often be treated with exercise and physical therapy, you may need surgery if your symptoms continue despite these treatments. The primary goal of surgery is to remove the source of compression on the nerves that supply the arm, forearm, and hand. This is typically accomplished by removing the first rib, anterior scalene muscle, and any additional abnormal muscles or fibrous bands. If there is an extra rib causing compression, it should also be removed.

Most patients with venous or arterial TOS will need surgical treatment. Surgery for venous and arterial TOS is very effective when performed before blood clots have a chance to form. If you have venous TOS and a blood clot has already formed, you will need emergency treatment to dissolve the clot and thin the blood. Surgery will reduce your risk of another clot or the return of symptoms.

What Is Thoracic Outlet Syndrome Q

How we care for thoracic outlet syndrome

Our goal in the Thoracic Outlet Syndrome Program is to return our patients to full function, This requires varying levels of intervention. York rehab Clinic has an extensive team of Osteopathy, Chiropractic, POhysiotherapy, Massage therapy and Acupuncture to help you.

Call to us at 416-350-1940 to make your appointment.