Thoracic Outlet Syndrome

Thoracic outlet syndrome (TOS) is a group of conditions caused by compression of the neurovascular structures — brachial plexus, subclavian artery or vein — as they pass through the thoracic outlet between the collarbone and first rib. It is notoriously difficult to diagnose and can mimic a variety of shoulder, neck, and arm conditions.

⏱️

Typical Recovery Time

3–6 months for neurogenic TOS with conservative treatment; vascular TOS may require urgent intervention

Symptoms

•Aching pain in the neck, shoulder, and arm
•Numbness and tingling in the arm and hand (especially ulnar)
•Arm fatigue with overhead use
•Hand weakness or clumsiness
•Color or temperature changes in the hand (vascular TOS)

Common Causes

•Cervical rib or anatomical variation
•Scalene muscle hypertrophy
•Poor posture (forward head, rounded shoulders)
•Repetitive overhead activity
•Prior clavicle fracture or shoulder trauma

Treatment Options

1Physical therapy focusing on posture, scalene stretching, and thoracic mobility

2Activity modification

3Botox injection into the scalene muscles (neurogenic TOS)

4Surgical first rib resection and scalenectomy for refractory cases

5Thrombolysis or anticoagulation for vascular TOS

When to See a Doctor

See a vascular surgeon or thoracic outlet specialist if you have arm color changes, swelling, or progressive neurologic symptoms — vascular TOS requires urgent evaluation.

Frequently Asked Questions

What is thoracic outlet syndrome?

Thoracic outlet syndrome occurs when nerves or blood vessels are compressed between the neck and shoulder. This can cause pain, numbness, or weakness in the arm. It is sometimes seen in athletes with repetitive overhead activity.

What causes thoracic outlet syndrome?

It can be caused by muscle tightness, poor posture, repetitive overhead activity, or anatomical differences. Sports that involve overhead motion may increase the risk. Trauma can also contribute.

What are the symptoms?

Symptoms include pain, numbness, tingling, or weakness in the shoulder, arm, or hand. Some people notice symptoms with certain positions or activities. Circulation changes may also occur in some cases.

How is it treated?

Treatment usually focuses on physical therapy to improve posture, flexibility, and strength. Activity modification is important. In more severe cases, additional procedures may be needed.

When can I return to activity?

Return to activity depends on symptom improvement and underlying cause. Many patients improve over weeks to months with therapy. Gradual return helps prevent recurrence.

Find a Sports Medicine Provider

Connect with a doctor, physical therapist, or imaging center near you.

Find a Provider for Thoracic Outlet Syndrome