What is thoracic outlet syndrome?

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From the Guidelines

Thoracic outlet syndrome (TOS) is a condition where the brachial plexus, subclavian artery, and/or subclavian vein become compressed at the superior thoracic outlet, resulting in pain, numbness, and tingling in the neck, shoulder, arm, or hand. This condition can be divided into three main types: neurogenic, venous, and arterial TOS, each with distinct symptoms and causes [ 1 ]. The symptoms of TOS typically include:

  • Pain in the neck, shoulder, arm, or hand
  • Numbness or tingling in the fingers
  • Weakened grip
  • Discoloration of the hand
  • Chronic arm and hand paresthesia, numbness, or weakness

The causes of TOS can be attributed to various factors, including:

  • Repetitive activities, such as swimming or throwing
  • Poor posture
  • Anatomical abnormalities, such as an extra rib or cervical rib
  • Trauma, including prior clavicular or rib fractures
  • Hypertrophy of the subclavius muscle, leading to narrowing of the costoclavicular space [ 1 ]

Early diagnosis and treatment of TOS are crucial to prevent permanent nerve damage or vascular complications. Treatment usually begins conservatively with physical therapy to strengthen chest muscles and improve posture, along with pain relievers like NSAIDs [ 1 ]. For severe cases that don't respond to conservative treatment, surgery may be necessary to remove the first rib or repair blood vessels. Understanding the various anatomic spaces, causes of narrowing, and resulting neurovascular changes is essential in choosing and interpreting radiological imaging performed to help diagnose TOS and plan for intervention [ 1 ].

From the Research

Definition and Classification of Thoracic Outlet Syndrome

  • Thoracic outlet syndrome (TOS) is a group of disorders caused by dynamic compression of blood vessels or nerves between the clavicle and first rib or cervical vertebral nerve roots 2.
  • TOS can be classified into three distinct types: neurogenic, venous, and arterial, with neurogenic being the most common type (95%) 3.
  • The syndrome presents with symptoms such as upper limb pain, numbness, tingling, or weakness, which can be exacerbated by shoulder or neck movement 2.

Causes and Risk Factors

  • The causes of TOS vary and can include abrupt movements, hypertrophy of the neck musculature, anatomical variations, edema, pregnancy, repeated overhead motions, and abnormal posture 2.
  • Congenital abnormalities, such as cervical ribs or fibrous bands, can also lead to TOS 4.
  • Neck trauma or repeated work stress can cause scalene muscle scarring or dislodging of a congenital cervical rib, compressing the brachial plexus 4.

Diagnosis and Treatment

  • Diagnosis of TOS can be established through history, physical examination maneuvers, and imaging 4.
  • Treatment options for TOS include surgery, medications, and exercise, with conservative management generally recommended as the first stage treatment 5.
  • Nonsurgical treatment may include anti-inflammatory medication, weight loss, physical therapy, and botulinum toxin injections 4.
  • Surgical treatments, such as brachial plexus decompression and scalenotomy, may be necessary for patients who have failed conservative therapy 4, 3.

References

Guideline

Guideline Directed Topic Overview

Dr.Oracle Medical Advisory Board & Editors, 2025

Research

Current management of thoracic outlet syndrome.

Current treatment options in cardiovascular medicine, 2009

Research

Thoracic outlet syndrome: a review.

Journal of shoulder and elbow surgery, 2022

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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