What are the symptoms of Thoracic Outlet Syndrome (TOS)?

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From the Guidelines

Thoracic outlet syndrome (TOS) typically presents with pain, numbness, and tingling in the neck, shoulder, arm, or hand due to compression of nerves and blood vessels in the thoracic outlet area, and symptoms can be categorized into neurogenic, arterial, or venous types. According to the American College of Radiology 1, the costoclavicular triangle, interscalene triangle, and pectoralis minor space are the three distinct spaces that can be implicated in TOS, resulting in different presentations.

Common Symptoms

  • Aching pain in the neck, shoulder, or arm that worsens with overhead activities
  • Weakness in the hand and arm
  • Coldness or color changes in the hand
  • Swelling of the arm
  • A weak pulse in the affected limb
  • Neurological symptoms like paresthesia (pins and needles sensation) along the arm and into the fourth and fifth fingers
  • Vascular symptoms may include discoloration of the hand, arm fatigue with activity, or even blood clots in severe cases

Causes and Risk Factors

Symptoms often worsen when raising the arms or with certain head positions, and many patients report that their symptoms intensify during activities that require arm elevation or after carrying heavy objects 1. The condition occurs when the nerves, arteries, or veins passing through the thoracic outlet (the space between your collarbone and first rib) become compressed, typically due to anatomical abnormalities, poor posture, trauma, or repetitive movements.

Importance of Medical Evaluation

If you experience these symptoms, especially if they're persistent or worsening, medical evaluation is crucial for proper diagnosis and treatment, as understanding the various anatomic spaces, causes of narrowing, and resulting neurovascular changes are important in choosing and interpreting radiological imaging 1.

From the Research

Thoracic Outlet Syndrome Symptoms

The symptoms of thoracic outlet syndrome (TOS) can vary depending on the compressed structure(s) and the type of TOS. Some common symptoms include:

  • Arm pain and swelling
  • Arm fatigue
  • Paresthesias (numbness or tingling sensations)
  • Weakness
  • Discoloration of the hand
  • Pain, numbness, or tingling in the shoulder and upper extremity area 2, 3, 4
  • Pallor (pale skin) 3

Classification of TOS

TOS can be classified into three categories:

  • Neurogenic TOS: caused by compression of the brachial plexus
  • Arterial TOS: caused by compression of the subclavian artery
  • Venous TOS: caused by compression of the subclavian vein 2, 5

Diagnosis and Treatment

Diagnosis of TOS is often made through a combination of physical examination, medical history, and imaging studies. Treatment options include:

  • Conservative management: physical therapy, lifestyle modifications, NSAIDs, and injection therapy 3, 6
  • Surgical decompression: for patients who have failed conservative therapy 2, 3
  • Rehabilitation: a vital component in the recovery process, especially for athletes 5

References

Guideline

Guideline Directed Topic Overview

Dr.Oracle Medical Advisory Board & Editors, 2025

Research

Thoracic outlet syndrome: a review.

Journal of shoulder and elbow surgery, 2022

Research

Thoracic Outlet Syndrome: A Narrative Review.

Journal of clinical medicine, 2021

Professional Medical Disclaimer

This information is intended for healthcare professionals. Any medical decision-making should rely on clinical judgment and independently verified information. The content provided herein does not replace professional discretion and should be considered supplementary to established clinical guidelines. Healthcare providers should verify all information against primary literature and current practice standards before application in patient care. Dr.Oracle assumes no liability for clinical decisions based on this content.

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