Thoracic Outlet Syndrome: Arm Numbness, Tingling and What It Means
Thoracic Outlet Syndrome: Arm Numbness, Tingling and What It Means
Quick summary
- Thoracic outlet syndrome (TOS) happens when nerves or blood vessels are compressed in the space between the collarbone, first rib and neck muscles.
- There are three types. Neurogenic TOS is by far the most common; the vascular types (venous and arterial) are much rarer but need urgent medical care (Illig et al., 2016).
- Neurogenic TOS often causes arm or hand tingling, heaviness and fatigue, typically worse with overhead or sustained arm positions. It overlaps with a pinched nerve in the neck and carpal tunnel syndrome, so careful assessment matters.
- For neurogenic TOS, a conservative program of posture, activity changes and targeted exercise is the usual first step before surgery is considered (Kuhn et al., 2015).
Tingling in the hand, an arm that feels heavy or tired, or symptoms that flare when you reach overhead or carry a bag can have several causes. One that is often overlooked is thoracic outlet syndrome. This article explains what it is, how it differs from other causes of arm symptoms, which signs are urgent, and how it is managed.
What is the thoracic outlet?
The thoracic outlet is the space between the base of the neck and the armpit, bordered by the collarbone, the first rib and the scalene muscles of the neck. The nerves that supply the arm (the brachial plexus) and the main artery and vein to the arm pass through it. If this space becomes narrowed, or the structures are irritated, symptoms can develop in the arm and hand.
The three types
The Society for Vascular Surgery reporting standards describe three forms (Illig et al., 2016):
- Neurogenic TOS: irritation of the brachial plexus nerves. This is by far the most common form.
- Venous TOS: compression of the subclavian vein, which can lead to a clot. Signs include sudden arm swelling, heaviness and a bluish or dusky colour.
- Arterial TOS: compression of the subclavian artery. This is the rarest form. Signs include a cold, pale, painful hand or fingers.
Venous and arterial TOS are medical emergencies. Sudden arm swelling, colour change, coldness or a pale hand need same-day medical care.
Symptoms of neurogenic TOS
- Pins and needles or numbness in the arm and hand, often the inner forearm and the ring and little fingers.
- A heavy, tired or aching arm, particularly with overhead work, reaching or carrying.
- Pain in the neck, shoulder or around the collarbone.
- Symptoms that worsen with sustained arm positions, such as driving, typing with the arms forward or hanging washing.
Is it TOS, a pinched nerve in the neck, or carpal tunnel?
These conditions can feel similar, and some people have more than one. A careful assessment looks at:
- Cervical radiculopathy (pinched neck nerve): often follows a dermatomal pattern and is commonly aggravated by neck movements, especially looking up or turning towards the painful side.
- Carpal tunnel syndrome: usually affects the thumb, index and middle fingers and often wakes people at night.
- Neurogenic TOS: typically linked to arm position, especially overhead or sustained postures, and may involve the whole arm.
There is no single definitive test for neurogenic TOS. Provocative tests can be positive in people without symptoms, so the diagnosis is based on the overall picture, and further tests such as nerve conduction studies or imaging are arranged when needed.
Management
For neurogenic TOS, a conservative program is the usual first step (Kuhn et al., 2015). This generally includes:
- Activity changes: reducing sustained overhead work and heavy shoulder bag carrying, and setting up your workstation so your arms rest closer to your body.
- Targeted exercise: strengthening the shoulder blade muscles, gentle stretches for the neck and chest muscles, and nerve gliding exercises.
- Breathing and posture: reducing overuse of the neck muscles during breathing, and building endurance in comfortable positions.
- Hands-on care: soft tissue work and mobilisation of the neck, upper back and first rib region may help some people as part of an active program.
If symptoms do not improve with a good conservative program, or there are signs of progressive weakness or vascular involvement, referral to a specialist is appropriate.
Arm tingling or heaviness that comes and goes with how you use your arms?
We assess the neck, shoulder and thoracic outlet together, rule out urgent causes and build a targeted plan.
Frequently Asked Questions
What does thoracic outlet syndrome feel like?
Neurogenic thoracic outlet syndrome commonly causes pins and needles, numbness, heaviness or fatigue in the arm and hand, often worse with overhead or sustained arm positions. Neck, shoulder or collarbone pain may also be present.
Is thoracic outlet syndrome serious?
The common neurogenic form is usually managed conservatively. The rarer vascular forms are emergencies: sudden arm swelling, a bluish colour, or a cold, pale hand need same-day medical care.
How is thoracic outlet syndrome different from a pinched nerve in the neck?
A pinched nerve in the neck is often aggravated by neck movements and follows a specific nerve pattern, while neurogenic thoracic outlet syndrome is typically linked to arm position. They can overlap, so a careful assessment is needed.
Can exercise help thoracic outlet syndrome?
For neurogenic thoracic outlet syndrome, a conservative program including activity changes, shoulder blade strengthening, stretching and nerve gliding is the usual first step before surgery is considered.
References
- Illig, K.A., Donahue, D., Duncan, A., et al. (2016). Reporting standards of the Society for Vascular Surgery for thoracic outlet syndrome. Journal of Vascular Surgery, 64(3), e23–e35.
- Kuhn, J.E., Lebus, G.F., & Bible, J.E. (2015). Thoracic outlet syndrome. Journal of the American Academy of Orthopaedic Surgeons, 23(4), 222–232.
This article is general information, not a diagnosis or a substitute for individual advice from your health professional.
