Thoracic outlet syndrome

NHS information about thoracic outlet syndrome, including the symptoms, possible causes and treatments.

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

Thoracic outlet syndrome affects your upper body, such as your arms, hands, chest and neck.

Symptoms include:

  • pain in your neck, head, upper back, chest, shoulder, arm or hand
  • numbness in your arm, hand, or fingers on 1 or both sides of your body
  • pins and needles
  • weakness in your shoulder, arm or hand
  • difficulty raising your arm, or it makes symptoms worse
  • your arm feels tired or heavy
  • swelling in your arm and hand
  • your arm or hand feels colder, warmer, or sweats more than usual
  • your arm or hand turns blue, grey, paler than usual or blotchy (mottled, with a pattern that looks like lace) – this can be harder to see on brown and black skin

It’s important to get medical help if you have symptoms of thoracic outlet syndrome.

See a GP if:

  • you think you have thoracic outlet syndrome

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

  • your arm is painful or cramping, swollen, warm and red (but redness can be harder to see on brown and black skin)

These could be signs of a blood clot caused by thoracic outlet syndrome. A blood clot can be life threatening if it's not treated quickly.

You can call 111 or get help from 111 online.

Call 999 if:

You have thoracic outlet syndrome and:

  • sudden breathlessness
  • severe chest pain (this may be worse when you breathe in)

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

They may refer you for tests, such an an X-ray or an ultrasound, CT or MRI scan of your chest and arms.

Some cases of thoracic outlet syndrome may be treated with:

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

Surgery may be recommended if:

  • your nerves are affected and physiotherapy has not helped
  • your blood vessels are affected and it's causing serious problems (such as a blood clot)
  • thoracic outlet syndrome is from an injury or a problem such as having an extra rib (cervical rib)

Thoracic outlet syndrome can happen if the nerves or blood vessels that pass through a small space at the top of your ribs (the thoracic outlet) become squashed.

Things that can lead to thoracic outlet syndrome include:

  • being born with an extra rib (known as a cervical rib), muscles or ligaments that make your thoracic outlet too small
  • poor posture
  • an injury to your 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)