Thoracic Outlet Syndrome (TOS)

What is thoracic outlet syndrome (TOS)?

Thoracic outlet syndrome (TOS) is a term used to describe a group of disorders that occur when there is compression, injury, or irritation of nerves and blood vessels in the lower neck and upper chest area. The space where these nerves and blood vessels is found is called the thoracic outlet. The three types of thoracic outlet syndrome are neurogenic thoracic outlet syndrome, venous thoracic outlet syndrome, and arterial thoracic outlet syndrome.

What causes thoracic outlet syndrome (TOS)?

When the blood vessels in the thoracic outlet are abnormally compressed, they become irritated which can cause TOS. This abnormal compression can be caused by an extra first rib, an old fracture, and other bony and soft tissue abnormalities. Other factors that may increase the risk of developing TOS include:

• Sleep disorders
• Stress or depression
• Repetitive injuries
• Poor posture
• Weightlifting

What are the symptoms of thoracic outlet syndrome (TOS)?

The symptoms of TOS include:

• Neck, shoulder, and arm pain
• Numbness or impaired circulation
• Weakness of the hands
• Cold sensitivity

How is thoracic outlet syndrome (TOS) diagnosed?

TOS is diagnosed using a complete physical exam and a series of diagnostic tests. These include:

• Chest X-ray
• CT scans
• MRI scans
• Arteriogram/venogram

A neurologist can help rule out other conditions with similar symptoms.

What are the available treatments for thoracic outlet syndrome (TOS)?

Although many cases of TOS cannot be prevented, the condition is not untreatable, and patients can undergo physical therapy and take pain medications. If patients are not finding these treatment options effective, surgery can be used in severe cases. In addition, thrombolytic medications can be given to dissolve blood clots if they form.

Where can I find more information on thoracic outlet syndrome (TOS)?

• Cleveland Clinic
• Mayo Clinic
• NIH