No study has counted the causes, but most are probably the back, neck or shoulderEmerging evidence
Pain in the upper (thoracic) back is common: across 33 studies, 3.5% to 34.8% of people had it over a year, more often children, teenagers and women, and it went with carrying backpacks, other muscle and joint pain and psychological stress. The NHS asks you to see a GP for back pain that comes from the top of your back, between your shoulders, and NHS inform says neck problems can cause pain in the shoulders, arms and upper back.
No study has counted the causes of pain under the shoulder blade as such. That most of it comes from the back, the neck or the shoulder is our inference from these studies and the ones below; the causes that aren't the back are rarer, but they come first on this page because they need help quickly.
Sources 1, 2, 3
The neck is a common sourceEmerging evidence
A review found 86 studies of a trapped nerve in the neck (cervical radiculopathy). Of the 81 that described where the pain was felt, 72% mentioned pain around the shoulder blade, most often with the C7 nerve root, and the review says shoulder-blade pain may come several weeks before arm pain. That figure counts studies, not people. In 25 people, the C5 nerve root was felt above the blade, C6 above it towards the back of the shoulder, C7 between the blades, and C8 between and over them.
The small joints of the neck refer pain in patterns that overlap, mapped in volunteers and in people whose pain was relieved by numbing injections. In 15 people, the joints at the top of the upper back (from the base of the neck to the third thoracic vertebra) referred pain to the area above the blade, its upper corner and the middle of the blade.
Sources 4, 5, 6, 7, 8
"A knot under the shoulder blade" is hard to pin downEmerging evidence
Tight, tender spots in the muscles (trigger points) are often blamed. But across 9 studies, examiners didn't agree reliably on finding them: agreement on a tight band in the muscle ranged from none to good, and no study tested the spots people blame for their pain. The review says examination can't currently be recommended as a reliable way to diagnose them. A sore muscle is a reasonable explanation, but not the only one, which is why this page checks the neck, the joints and the warning signs.
Source 9
The heart, the aorta and the lungsStrong evidence
The NHS lists pain that spreads to the left or right arm, or the neck, jaw, shoulder, stomach or back, among the 999 signs of a heart attack. The British Heart Foundation lists pain spreading to the upper back for women, and in a review of studies from 1990 to 2009, women were less likely than men to have chest pain with a heart attack (odds ratio 0.63) and more likely to have tiredness, neck pain, fainting, nausea, right arm pain, dizziness and jaw pain. The National Institute for Health and Care Excellence (NICE) says don't assess heart symptoms differently in men and women, and that a normal electrocardiogram (ECG) doesn't rule out a heart attack.
A tear in the aorta is rare but serious: in a registry of 464 people, sudden, severe, sharp pain was the commonest complaint, the classic signs were often missing, and the ECG was normal in 31%. The NHS lists "pain in your chest or upper back" among the 999 signs of a clot in the lungs, and says pleurisy's sharp pain when you breathe in may spread to your shoulders and back.
Sources 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20
The gallbladder, the pancreas and shinglesStrong evidence
Gallstone pain (biliary colic) is constant pain lasting more than 30 minutes, in the middle of the tummy or just under the ribs on the right, the NHS says. NHS inform adds that it usually lasts 1 to 5 hours, may spread from there to your side or shoulder blade, is sometimes triggered by fatty food and may wake you at night; when the gallbladder is inflamed, the pain travels towards the shoulder blade, usually lasts more than 5 hours and comes with a temperature of 38C or above. The nhs.uk gallstones page doesn't mention the shoulder blade.
Acute pancreatitis causes sudden, severe tummy pain that can spread to the sides and back, the NHS says, often feeling better when you lean forward. NHS inform describes a severe, dull pain around the top of the stomach that can travel along your back or below your left shoulder blade. Shingles starts as a tingling or painful area of skin, with a rash on one side only a few days later, usually on the chest and tummy; in 503 people with shingles, the chest and upper back nerves were the commonest site (50.9%).
Sources 21, 22, 23, 24, 25, 26
Lung tumours and rarer shoulder-blade problemsEmerging evidence
The NHS lists chest or shoulder pain among the symptoms of lung cancer, with a cough that won't go away, breathlessness, coughing up blood and losing weight. A tumour at the top of the lung (a Pancoast tumour) can cause severe, constant shoulder and arm pain, with wasting of the small muscles of the hand. NICE offers people aged 40 and over an urgent chest X-ray for two or more unexplained symptoms such as a cough, breathlessness or chest pain, or for just one if they have ever smoked.
Rarer shoulder-blade problems are described mainly in case reports and small series: a trapped nerve to the rhomboid muscles (the dorsal scapular nerve), with pain along the inner border and slight winging; a squeezed nerve over the back of the blade (the suprascapular nerve), more often in overhead athletes and people with large rotator cuff tears; a grinding, snapping shoulder blade; and notalgia paraesthetica, an itchy, uncomfortable patch on the upper back from irritated skin nerves.
Sources 27, 28, 29, 30, 31, 32, 33, 34
Left or right rarely decides itEmerging evidence
The heart can send pain to either arm and to the back. Gallstone pain is more often under the right ribs, and NHS inform says it may spread to the shoulder blade; NHS inform says pancreatitis can be felt below the left shoulder blade; but both can spread across the back. Muscles, joints and the neck can be sore on either side. The side is a clue, not an answer: the other symptoms matter more.
Sources 12, 10, 21, 22, 23, 24
When a test helpsStrong evidence
A suspected heart attack needs an ECG as soon as possible and blood tests; a normal ECG doesn't rule it out. A suspected clot in the lungs is scored by a clinician, then scanned with a computed tomography (CT) pulmonary angiogram if a clot is likely. Pleurisy and pneumonia may need a chest X-ray.
Suspected gallstones need liver blood tests and an ultrasound scan, and pancreatitis is diagnosed with blood tests and sometimes a CT scan. Most back problems don't need an X-ray or a magnetic resonance imaging (MRI) scan, NHS inform says; nerve symptoms that keep getting worse or don't settle may need an MRI and a specialist's review (our pinched nerve guide).
Sources 14, 11, 35, 19, 28, 36, 23, 37
How it usually goesEmerging evidence
Most neck problems should begin to settle within 8 weeks, with the biggest change in the first couple of weeks, NHS inform says, and the NHS says back pain usually improves within a few weeks. A trapped neck nerve can start with shoulder-blade pain before the arm pain. The shingles rash can take up to 4 weeks to heal. No one can promise a date.
Sources 3, 37, 2, 25