Thoracic Outlet Syndrome

Overview of Thoracic Outlet Syndrome

Thoracic outlet syndrome refers to the compression of blood vessels or nerves in the space between the collarbone and the first rib. This can cause pain in the shoulders, neck, and fingers numbness.

It involves many external factors to cause thoracic outlet syndrome such as repetitive injuries, car accidents, etc. In order to improve it, mostly physical therapy and pain reliever steps are taken for acute to moderate injuries. In other cases, a doctor may suggest surgeries according to the condition.

Prevalence of Thoracic Outlet Syndrome

Globally, about 30 to 80 out of 1000 cases of thoracic outlet syndrome have been reported. Women are more affected by this disease as compared to males due to their poor posture, muscular development, or both. 

Signs and Symptoms of Thoracic Outlet Syndrome

The symptoms of thoracic outlet syndrome vary according to its type. Some are as follows:

1. Neurogenic Thoracic Outlet Syndrome Symptoms

  • Feeling pain or weakness in the shoulder and arm
  • Tingling in the fingers
  • Atrophy (shrinking and weakness) in the thumb and palm muscles leads to the thumb

Symptoms may get worse if arms stay longer in one position. 

2. Venous Thoracic Outlet Syndrome Symptoms

  • Oedema (swelling) of the arm, hand, or fingers
  • Appears blue color of the hand and arm
  • Painful tingling in the hand and arm
  • Veins are prominent in the shoulder, neck, and hand region

3. Arterial Thoracic Outlet Syndrome Symptoms

  • A cold and pale hand
  • Pain in the hand and arm, especially during overhead motions of the arm
  • Embolism (blockage) of an artery in the hand or arm

Types of Thoracic Outlet Syndrome

The types of thoracic outlet syndrome are based on the nerves, veins, or arteries that are connected to different areas of the body. If any one part of them is compressed, it is divided into the following types of the syndrome: 

  • Neurogenic thoracic outlet syndrome is caused by the compression of nerves transferred from the neck to the arms. About 90% of people are affected by neurogenesis.
  • Venous thoracic outlet syndrome is due to a compressed vein that leads to upper body thrombosis. Almost 5% of people suffer from venous thoracic outlet syndrome.
  • Arterial thoracic outlet syndrome results from bony abnormalities in the lower neck and upper chest. It is a congenital type of syndrome that affects only 1% of people.
  • In some cases, both venous and arterial syndrome combine together known as vascular thoracic outlet syndrome.

Causes of Thoracic Outlet Syndrome

Thoracic outlet syndrome usually shows its symptoms as the thoracic outlet becomes constricted and compresses the nerves and blood vessels. The exact cause is not clearly defined but develops due to the following conditions:

  1. Extra Rib Condition

In some cases, pregnant women deliver a baby with an extra rib (present above their first rib). This results in reducing the size of their thoracic outlet and compresses nerves and blood vessels.

  1. Poor Posture and Obesity

People with deformed postures or excess fat (obesity) may have increased pressure on their joints. This causes constriction of the thoracic outlet.

  1. Injury

Some dangerous accidents or other traumatic injuries can cause compression of the thoracic outlet as well as the vessels and nerves in this area.

  1. Overuse of the Shoulders and Arms

Excessive use of shoulders and arms due to repetitive activities such as working at a computer or lifting heavy objects above the head can increase damage to the tissues in the thoracic outlet. The size of the thoracic outlet may shrink as time passes by, which increases pressure on the vessels and nerves.


Risk Factors of Thoracic Outlet Syndrome

Multiple factors are involved to increase the risk of thoracic outlet syndrome including,

  • Heavy weight lifting: People who have extreme usage of the upper body part are more likely to develop this condition.
  • Poor posture: Poor body posture is another important risk factor for the disease.
  • Sex: Females are more prone to thoracic outlet syndrome than males.
  • Obesity: Being overweight or obese is an important risk factor for the disease. 
  • Age: People between 20 and 40 years old may be at increased risk of thoracic outlet syndrome, especially young adults.



For the prevention of thoracic outlet syndrome, the following steps are taken to reduce the symptoms and prevent them from relapse.

  • Improve the posture while sitting or standing
  • Stretch the muscles during work or school
  • Maintaining a healthy weight
  • Performing strengthening exercises
  • Avoid lifting heavy objects
  • Do not carry heavy bags on the shoulders
  • Avoid doing repetitive movements


It is very difficult to diagnose thoracic outlet syndrome but varies from person to person. A doctor firstly reviews the symptoms, medical history and physical examination. After that, the following tests may recommend:

1. Provocation Tests  

These tests are conducted to determine the patient's associated conditions from different angles. For example, a doctor moves the arms, neck or shoulders at various positions to examine the symptoms properly

2. Imaging and Nerve Study Tests

To confirm any abnormalities in the thoracic region, a doctor may recommend one or more of the following tests:

  • X-ray: It is suggested to reveal the mainly for identifying the extra rib or any other conditions that may cause symptoms.

  • Ultrasound: Helps to determine the vascular problems of thoracic outlet syndrome.

  • Computerized Tomography (CT) Scan: It is performed to see the cross-sectional images of the body visually as the scan is obtained. This helps to check the location and cause of blood vessel compression.

  • Magnetic Resonance Imaging (MRI): MRI test is an advanced and powerful imaging test that determines the location and cause of blood vessel compression. Also reveals that congenital abnormalities such as an extra rib or fibrous band connecting to the rib and spine may cause potential symptoms.

  • Angiography: In a few cases, an intravenous dye is injected into the patients before the CT scan and MRI in case of CT angiography Neck, and Brain test. This makes the blood vessels more clear and more visible than usual.

  • Arteriography and Venography:  This helps to show the X-ray images of arteries and veins which are more visible. To determine whether the vessels are compressed or not and what's the main cause of it.

Doctors dissolve the clot of blood in the vein or artery through the insertion of solution into them. Following are the tests that are useful for eliminating the clot.

  • Electromyography (EMG): During an EMG, a doctor inserts a needle electrode through the skin into various muscles. The test is performed for the evaluation of electrical activity in muscles when they contract and when they're at rest.

  • Nerve Conduction Study:  In this test, a doctor passes a low amount of electric current to measure whether the nerves are functioning properly or not. This is done by sending the impulses to different muscle areas of the body. By doing this, it helps to determine the nerve damage if any.

Treatment of Thoracic Outlet Syndrome | When to Consult a Doctor

The best approach to treat thoracic outlet syndrome is the implementation of conservative therapies on the basis of the diagnosis of people. 

Treatment may involve the following therapies:

  • Physical Therapy

The first line of treatment that may be recommended is doing physical activities. These activities stretch the shoulder muscles and make the thoracic outlet open. Also, improve the motion of the body and posture to release the pressure from blood vessels and nerves connected to the thoracic outlet. 

  • Medications

Typically a doctor may prescribe anti-inflammatory medications, pain medications, or muscle relaxants for reducing inflammation, and pain, and increased muscle relaxation.

  • Clot-Dissolving Medications

People are suffering from thoracic outlet syndrome along with blood clots in veins or arteries, treated with clot-dissolving injections into the affected area.

  • Surgery 

Surgery is the last option doctors may recommend if they suspect any associated complications with thoracic outlet syndrome such as brachial plexus. This surgical treatment may have a risk of recurring symptoms.

There are the following approaches to treat thoracic outlet syndrome surgically and relieve the patients from compressed veins, arteries, and nerves.

  • The transaxillary approach is a strategy to treat the chest area, muscles accumulate in front of ribs or compressed vessels. 
  • The supraclavicular approach deals with the repair of compressed blood vessels.
  • The infraclavicular approach is used for the compressed veins of the collarbone and across the chest area. 

During surgery anti-clotting agents are also used if patients have any blood clots in vessels.


In case you exhibit any concerning signs and symptoms of thoracic outlet syndrome, consult a medical professional as soon as possible.