What is Thoracic Outlet Syndrome?
Thoracic Outlet Syndrome (TOS) is a group of conditions caused by compression of the nerves or blood vessels that pass through the space between your collarbone and first rib — known as the thoracic outlet. This can lead to pain, numbness, and weakness in the shoulder, arm, and hand.
TOS occurs when the space in the upper chest becomes narrowed or crowded, putting pressure on the nerves (neurogenic TOS), veins (venous TOS), or arteries (arterial TOS) that run from the neck to the arm. It can affect daily activities and worsen with certain movements or posture.
Common Causes of Thoracic Outlet Syndrome
Common causes of TOS include:
- Poor posture or slouching
- Repetitive overhead movements (common in athletes and manual laborers)
- Trauma, such as a car accident or sports injury
- A congenital abnormality, like an extra rib (cervical rib)
- Tumors or scar tissue pressing on nerves or vessels
- Pregnancy, which can change posture and increase joint looseness
Symptoms of Thoracic Outlet Syndrome
Symptoms vary depending on the type of TOS, but may include:
- Numbness or tingling in the fingers, hand, or arm
- Weakness or fatigue in the affected arm
- Pain in the neck, shoulder, or arm
- Swelling, discoloration, or coldness in the arm or hand
- A weakened grip or clumsiness with hand movements
Symptoms are often triggered or worsened by lifting the arms overhead.
Thoracic Outlet Syndrome Treatment
Treatment for Thoracic Outlet Syndrome typically begins with conservative options. Physical therapy plays a key role in strengthening the muscles around the shoulder and improving posture, which can relieve pressure on the affected nerves or blood vessels. Many patients also benefit from modifying their daily activities to avoid repetitive arm movements or overhead lifting that aggravates symptoms.
In some cases, anti-inflammatory medications or muscle relaxants are prescribed to manage pain and reduce tension. If symptoms persist or are severe, targeted injections may help decrease inflammation.
For cases that don’t respond to non-surgical methods, surgery may be recommended to remove an extra rib or release compressed tissue to create more space in the thoracic outlet.
Frequently Asked Questions
TOS can range from mild to serious, depending on the type and severity. While some cases cause discomfort and limited function, others—especially those involving compressed blood vessels—can lead to complications if not treated properly.
You should see a doctor if you experience ongoing numbness, tingling, pain, or weakness in your arm, shoulder, or hand—especially if these symptoms get worse with certain movements or interfere with daily activities.
Diagnosis typically involves a physical exam, a review of your symptoms, and imaging tests such as X-rays, MRI, or nerve conduction studies to identify the source of compression.
Physical therapy focuses on posture correction, stretching tight muscles, strengthening the shoulder and neck area, and teaching techniques to reduce nerve or vessel compression during daily movements.
Recovery can take several months, depending on the procedure and the individual. Most patients start physical therapy shortly after surgery and gradually return to normal activities over 3 to 6 months.
Without treatment, symptoms may worsen over time and lead to long-term nerve damage, decreased arm strength, or circulation problems. Early diagnosis and intervention can help prevent complications.
