The Arm Tingling That Isn't Carpal Tunnel: Thoracic Outlet Syndrome
Written by Dr Russell Jensen, Principal Chiropractor (AHPRA: CHI0001927257), Southside Spine and Sport. Published May 2026. For general information only, not medical advice. Always consult a qualified health professional for assessment and treatment.
If you have tingling or numbness running into your arm and hand, the first thing most people think of is carpal tunnel. Sometimes that is right but Carpal Tunnel is almost exclusively felt in the hand. What if I told you that there is another condition that produces similar symptoms, gets missed far more often, and starts much higher up: thoracic outlet syndrome.
It produces pain, tingling, numbness, or weakness in the neck, shoulder, arm, and hand, and it is regularly mistaken for other problems: a disc in the neck, carpal tunnel or a rotator cuff issue. When it is correctly identified as a neurogenic problem, and the specific sites of nerve compression are treated directly, it tends to respond very well to the kind of conservative, hands-on approach we use at Southside Spine and Sport.
In this article I will explain what thoracic outlet syndrome is, the important difference between the two main forms, and the specific way we assess and treat it.
What is thoracic outlet syndrome?
The thoracic outlet is a space between your collarbone and your first rib. A bundle of nerves (the brachial plexus) and major blood vessels pass through this space on their way from the neck into the arm. Thoracic outlet syndrome (TOS) occurs when these structures are compressed somewhere in that space.
That compression can happen for several reasons: tight or overdeveloped muscles in the neck and chest, postural patterns that narrow the space, an extra rib (a cervical rib), or scar tissue and adhesions that restrict the normal movement of the nerves through the region.
The two forms: neurogenic and vascular
This distinction matters more than any other when it comes to thoracic outlet syndrome, so it is worth being clear about it.
Neurogenic TOS
This is by far the most common form, accounting for the large majority of cases. It involves compression of the nerves of the brachial plexus. The symptoms are sensory and motor: pain, tingling, numbness, and weakness through the arm and hand. This is the form that responds well to conservative treatment, and it is the form this page focuses on.
Vascular TOS
This is much less common but more serious. It involves compression of the artery or vein passing through the thoracic outlet rather than the nerves. It can produce symptoms like swelling, colour changes in the arm or hand, coldness, or a feeling of heaviness and fatigue, and it sometimes requires urgent medical or surgical management.
“Distinguishing neurogenic from vascular TOS is the essential first step in any assessment. The two can look similar at a glance but require very different management. Part of a thorough examination is screening for the signs of vascular involvement so that anything requiring urgent medical attention is identified early and referred appropriately. The information on this page relates to the neurogenic form.”
Symptoms of neurogenic thoracic outlet syndrome
Neurogenic TOS symptoms often develop gradually and can be vague early on, which is part of why it gets missed. Common features include:
Aching or burning pain in the neck, shoulder, or down the arm
Tingling or numbness in the arm or hand, often affecting the ring and little fingers
Weakness or fatigue in the arm, particularly with overhead activity
Symptoms that worsen when the arms are raised or held overhead, for example hanging washing, reaching into a high cupboard, or driving
A feeling of heaviness in the arm
Symptoms that are linked to posture, repetitive overhead work, or a previous neck injury
Because these symptoms overlap with several other conditions, an accurate diagnosis depends on a careful clinical examination rather than symptoms alone.
Why it gets misdiagnosed
The nerves involved in neurogenic TOS travel from the neck all the way into the hand, so the symptoms can appear anywhere along that path. This is why TOS is so often mistaken for other conditions: a cervical disc problem, carpal tunnel syndrome at the wrist, a shoulder issue, or general nerve pain.
It is also possible to have more than one site of compression along the same nerve at the same time, which can make the picture confusing if each region is assessed in isolation rather than as a whole. A thorough assessment looks at the entire course of the nerve, not just the spot where the symptoms are felt most.
Learn more about how we approach nerve pain generally on our nerve pain page.
How we treat thoracic outlet syndrome at Southside Spine and Sport
This is where our particular approach to nerve entrapment conditions is well suited to the problem. Neurogenic TOS is, at its core, a nerve compression problem, and the nerves are compressed at specific, identifiable locations. Our treatment is directed at those specific sites rather than at the symptoms in general.
The main areas we assess and treat in neurogenic TOS are:
The scalene muscles and cervical nerve roots
The brachial plexus nerves pass between the scalene muscles in the side of the neck, and emerge from the cervical nerve roots in the neck itself. Tightness, overdevelopment (think poor breathing mechanics), or adhesion around the scalenes is one of the most common sites of compression. We apply targeted soft tissue therapy here to reduce the compression and restore normal movement of the nerves as they pass between these muscles.
The pectoralis minor
Further along the nerve's path, the brachial plexus passes underneath the pectoralis minor muscle at the front of the shoulder. A tight or contracted pec minor, which is very common in people with rounded-forward posture, can compress the nerves against the structures beneath it and cause them to become "stuck." People with poor shoulder range of motion can also run into trouble here, because the nerve loses the normal gliding movement that helps keep it mobile and "unstuck." Releasing and restoring length to this muscle, and restoring normal shoulder movement, is a key part of treatment for many TOS presentations.
The subscapularis region
The neurovascular bundle also passes by the subscapularis on the underside of the shoulder blade, and the nerves can become adhered against the subscapularis muscle, its tendon, or other adjacent tissues, losing their normal gliding motion. This area is frequently missed, and even when it is diagnosed it is often treated incorrectly, which is why so many people never get lasting relief from their symptoms. We assess and treat this region as part of addressing the full pathway of the nerve.
“The reason we treat across all of these sites is that neurogenic TOS frequently involves more than one point of compression along the same nerve. Treating only the most obvious site often produces partial or temporary relief. Assessing and addressing the entire pathway, from the cervical nerve roots through the scalenes, under the pec minor, and around the subscapularis, is what tends to produce lasting change. This is the same precision, full-pathway approach we use for other nerve entrapment conditions like cluneal nerve pain and deep gluteal sciatica.”
Beyond the hands-on treatment
Beyond the hands-on treatment, our approach also includes postural advice to address the patterns that contribute to narrowing of the thoracic outlet space in the first place, and progressive strengthening of the shoulder girdle, and in some cases the neck, so that these improvements hold. We may also use shockwave therapy where it is indicated and safe to do so around the shoulder, to assist these changes.
Learn more about our soft tissue therapy, adhesion release, and shockwave therapy
When to seek urgent care
“Most thoracic outlet syndrome is neurogenic and is not a medical emergency. However, the following can indicate vascular involvement or another serious problem and warrant prompt medical assessment: significant swelling of the arm or hand, a marked change in the colour of the arm or hand (pale, blue, or dusky), the arm or hand feeling cold compared to the other side, or sudden severe symptoms. If you experience these, seek medical attention rather than waiting for a chiropractic appointment.”
How long does recovery take?
For neurogenic TOS, most people see meaningful improvement within the first couple of sessions once we correctly target your specific sites of compression or irritation, combined with postural advice and strengthening exercise. Longer standing cases, or those where the nerves have been compressed in multiple locations over a long period, can take longer, because the affected tissues, including the nerve itself, need time to settle, calm down, and become less sensitive.
The most important factor in recovery, as with most nerve entrapment conditions, is accurate diagnosis early, and specific treatment that addresses the right tissues at the right sites.
Frequently asked questions
What is thoracic outlet syndrome?
Thoracic outlet syndrome is compression of the nerves or blood vessels that pass through the space between your collarbone and first rib on their way from the neck into the arm. The most common form, neurogenic TOS, involves compression of the brachial plexus nerves and produces pain, tingling, numbness, or weakness in the neck, shoulder, arm, or hand.
What is the difference between neurogenic and vascular TOS?
Neurogenic TOS involves the nerves and accounts for the large majority of cases. It usually responds well to conservative treatment. Vascular TOS involves the artery or vein, is far less common but more serious, and can require urgent medical or surgical care. Telling them apart is an essential first step because their management is very different.
What are the symptoms of neurogenic TOS?
Aching or burning pain in the neck, shoulder, or arm, tingling or numbness in the arm or hand (often the ring and little fingers), weakness or fatigue with overhead activity, and symptoms that worsen with the arms raised. Symptoms often develop gradually and can be linked to posture, repetitive overhead work, or a previous neck injury.
How is neurogenic TOS treated?
We use targeted soft tissue therapy or shockwave therapy (where indicated and safe) at the specific sites where the nerves are commonly compressed: the scalene muscles and cervical nerve roots, the pectoralis minor, and the tissues around the subscapularis. This is combined with nerve mobilisation, postural retraining, and progressive strengthening to restore normal nerve movement and reduce the compression driving the symptoms.
Can TOS be treated without surgery?
Yes. Most neurogenic TOS responds to conservative treatment without surgery. Surgery is generally reserved for vascular TOS or for neurogenic cases that have not responded to a thorough course of conservative care.
Persistent neck, shoulder, arm, or hand symptoms that have been hard to pin down, or that have been treated as something else without lasting improvement? A proper assessment will determine whether thoracic outlet syndrome is involved and which sites need to be addressed.
Book an appointment online or send us a message if you would like to ask a question first. We are based in Bicton and see patients from across Perth's southern suburbs.
