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Thoracic outlet syndrome

Thoracic outlet syndrome is where nerves or blood vessels near the top of the ribs get squashed. It can be treated with physiotherapy and medicine.

Check if you have thoracic outlet syndrome

Thoracic outlet syndrome usually affects 1 arm and hand.

Symptoms include:

  • pins and needles – this can be worse at night and wake you up
  • the affected arm gets tired easily
  • pain and swelling in the affected arm
  • the affected hand and arm feels cold
  • the skin on the hand turns blue, grey or pale – this can be harder to see on brown or black skin

Non-urgent advice: See a GP if:

  • you think you have thoracic outlet syndrome

Urgent advice: Ask for an urgent GP appointment or get help from NHS 111 if:

  • you have throbbing or cramping pain, swelling, redness and warmth in 1 arm

These could be signs of a blood clot caused by thoracic outlet syndrome. Blood clots can be life threatening if not treated quickly.

You can call 111 or get help from 111 online.

Immediate action required: Call 999 if:

  • you have sudden breathlessness, sharp chest pain (this may be worse when you breathe in) and a cough or coughing up blood

What happens at your appointment

If you have symptoms of thoracic outlet syndrome, a GP will usually check your arms, chest and neck to look for possible causes of your symptoms.

They may refer you for an X-ray or other tests, such as a CT scan or MRI scan.

Treatment for thoracic outlet syndrome

Thoracic outlet syndrome is usually treated with:

  • physiotherapy – a physiotherapist can teach you some stretching and strengthening exercises that reduce pressure on nerves and blood vessels
  • medicines – you may need medicines to help treat pain, relax muscles, improve circulation and reduce your risk of blood clots

Surgery may sometimes be recommended if you're having serious problems (such as blood clots) and other treatments have not worked.

For example, if thoracic outlet syndrome is caused by having an extra rib (cervical rib), surgery to remove it may be recommended.

Causes of thoracic outlet syndrome

Thoracic outlet syndrome can happen if the nerves or blood vessels running along the top of the rib cage (an area called the thoracic outlet) become squashed.

Things that can lead to thoracic outlet syndrome include:

  • being born with an extra rib – this is known as a cervical rib
  • poor posture
  • having large breasts
  • an injury to the chest, neck or ribs (such as a car accident)
  • jobs or activities that involve lots of repetitive arm movements (for example if you're a builder or do lots of swimming)
  • gaining a lot of muscle (for example, if you're a body builder)

Page last reviewed: 14 December 2023
Next review due: 14 December 2026