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What Is Thoracic Outlet Syndrome?

By Apricus Health

15th February 2023

Thoracic outlet syndrome is a condition that makes the normal day-to-day tasks painful, difficult, and challenging. A rare condition that is estimated to affect just 1% of the population, the general public are often misinformed about thoracic outlet syndrome.

So, what is thoracic outlet syndrome (TOS)? What are the symptoms of this condition? And can it be treated? Read on to learn everything you need to know about TOS.

What is Thoracic Outlet Syndrome?

Thoracic outlet syndrome (or TOS for short) is a general term used to describe a group of conditions that affect the thoracic outlet. This part of your body is located between your neck and your armpit. When suffering from thoracic outlet syndrome, your nerves and blood vessels in that area become compressed. As a result, various unpleasant symptoms are experienced, like pain in the shoulder and neck, as well as numbness and tingling in the same area. 

When diagnosing thoracic outlet syndrome, physicians differentiate between two types of thoracic outlet syndrome. Each type of thoracic outlet syndrome can affect different parts of the body, will require different treatment and can cause different experienced symptoms: neurogenic TOS affects the nerves; vascular TOS (a collective term for venous TOS and arterial TOS) affects the blood vessels.

Thoracic Outlet Syndrome Symptoms

Depending on the type of thoracic outlet syndrome, common symptoms generally include:

  1. Numb feeling and tingling in the fingers
  2. Weakness in arms and hands
  3. Aches and pain in the shoulder and neck area
  4. Weakened or lost muscle function in arms and hands
  5. Weakened or lost coordination and agility in the hands
  6. Fatigue and cramping in arm and hands
  7. Feeling of heaviness in the arm and hands
  8. Cold and discoloured fingers
  9. Swelling of the hand and fingers
  10. Pain and discomfort when lifting the arm

Neurogenic Thoracic Outlet Syndrome: 

With neurogenic thoracic outlet syndrome, symptoms like pain and weakness, tingling sensations, and fatigue of the affected limb are more common than with other types of thoracic outlet syndrome.  

Vascular Thoracic Outlet Syndrome

Those with vascular thoracic outlet syndrome are more likely to experience swelling, discolouration, coldness, painful tingling, and pain when completing overhead motions with the affected limb.

While each type of thoracic outlet syndrome varies in symptoms and affected areas, these symptoms are not exclusive to one type. Symptoms vary from person to person in appearance and intensity.

What Causes Thoracic Outlet Syndrome?

Common causes of thoracic outlet syndrome include physical injury or trauma, poor posture, repetitive injuries, anatomical abnormalities, and pregnancy. However, in some cases, the cause of TOS is not identified.


Injuries, such as neck and shoulder trauma and complications caused by other medical diagnoses, such as lung tumours and aneurysms, can affect the thoracic outlet. Therefore, they can be a cause of thoracic outlet syndrome. 

Poor Posture

One of the more common causes of thoracic outlet syndrome is poor posture, for example, slouching or hunching over while working at an office desk. This position can put extra pressure on the thoracic outlet, pressuring the nerves and blood vessels.

Repetitive Movements

Repetitive movements, for example, when playing an instrument or working as a tradie, can increases the risk of thoracic outlet syndrome.


Some physical characteristics may increase the risk of thoracic outlet syndrome. A narrow thoracic outlet makes it more likely to block nerves and vessels. Similarly, having a cervical rib, which some people are born with, increases the likelihood of thoracic outlet syndrome. 


During pregnancy, the joints loosen, and the body inevitably gains weight – this can place undue pressure on the joints, leading to developing thoracic outlet syndrome.

Thoracic Outlet Syndrome Treatment

While Thoracic Outlet Syndrome is not entirely preventable, there are treatments available that will effectively cure the condition, these may include: 


Medication is used to treat symptoms and ease pain, fatigue, and the uncomfortable tingling sensations. Non-steroidal anti-inflammatory drugs (NSAIDs) and muscle relaxants are common medications prescribed to help with pain relief and inflammation. In rare cases, medical procedures may be necessary. 


Physiotherapy and physical therapy are by far the most common and effective treatments for thoracic outlet syndrome.

With a physiotherapist, occupational therapist, or hand therapist, you’ll be prescribed and undertake thoracic outlet syndrome exercises that focus on the neck, shoulder, and upper back. These types of exercises and manual therapy will improve posture, reduce tension, and increase blood flow.

Thoracic Outlet Syndrome Exercises

Physical therapy exercises and treatment will vary depending on the type of thoracic outlet syndrome and how the condition is experienced. Here are three standard thoracic outlet syndrome exercises:

  • Shoulder Blade Squeeze: this involves squeezing your shoulder blades together and holding the position for five to ten seconds. This exercise is completed by sitting and standing.
  • Chest Stretches: This exercise involves stretching out the thoracic outlet by expanding the chest. To complete the exercise, stand in a door frame with your arms spread-out . While your hands rest on the doorframe, step forward with one foot and lean into it to feel your chest and shoulders stretch as your hands remain behind you. Hold the position for 15-30 seconds before repeating on the other side. 
  • Neck Stretches: Neck stretches may be prescribed depending on your symptoms and discomfort. To complete this exercise, bring your left ear down to your left shoulder. Use your right hand to bring the head down as far as possible (without hurting yourself) and hold the position for 15-30 seconds. Repeat on the other side. 

If you have been diagnosed with thoracic outlet syndrome, or if you think you have the signs and symptoms,  it’s important to discuss these exercises with a qualified health professional to get their advice and treatment recommendations specific to your case. At Apricus Health our hand therapy team is able to assess your condition and get you on the road to recovery.