What it is
The vertebrae are normally shaped like short, flat cylinders. In Scheuermann's disease, the front edge of some vertebrae in the upper back grows more slowly than the back edge during the growth spurt, so they become wedge-shaped and the spine curves forward. The NHS puts it like this: 'The back of the bones in the spine (vertebrae) grow quicker than the front.' The cause is unknown.
It is defined on an X-ray: three neighbouring vertebrae each wedged by at least 5 degrees, usually with an upper-back curve over 40 to 45 degrees, uneven end plates (the surfaces next to the discs) and small dents in them called Schmorl's nodes. A normal upper-back curve measures about 20 to 45 degrees. The wedging is usually in the middle of the upper back (in 150 patients, most often the 7th and 8th thoracic vertebrae), and a less common lower form sits where the upper and lower back meet, often in athletic boys with back pain.
Sources 1, 2, 3, 4, 5, 6, 7, 8
Who gets itStrong evidence
Population X-ray studies found it in 2.2% of 454 people aged 15 to 40 in Chile and 4.0% of 2,753 Dutch adults aged 45 and over, and 2.8% of almost 35,000 Danish twins said a doctor had diagnosed it. A US review gives a range up to 8%. It runs in families: in the twin study, heritability (how much of the difference between people is down to genes) was 74%.
It is diagnosed about twice as often in boys and men (3.6% against 2.1% in the twins), but the two X-ray studies found no clear difference between the sexes, so boys may be noticed more. It usually shows during or just after the puberty growth spurt, and most teenagers are diagnosed at 12 to 15.
Sources 9, 10, 11, 3, 2, 5
A slouch or Scheuermann's? How to tell
Postural rounding (a slouch) is a smooth, gentle curve that straightens when you stand up straight or lie flat, is more common in girls, rarely hurts and doesn't get worse. Scheuermann's disease is a sharper, stiffer curve that doesn't straighten by effort: 'Kids can't straighten their curve by standing up', as one children's health service puts it. It shows most from the side when bending forward, which is how a doctor looks for it (the forward bend test). Tight hamstrings are common.
About half of children with it have back pain, usually at the peak of the curve or in the low back, worse with activity and with long spells of sitting or standing. It is a common cause of mid-back pain in teenagers, and a 2023 review calls it the most common cause of upper-back pain at that age. In 150 patients, the size of the curve was linked with how people rated their back's appearance, not with how much it hurt.
Sources 6, 2, 1, 12, 13, 7
How it's diagnosed, and what scan reports do and don't meanEmerging evidence
A GP refers to a specialist, who examines the back and arranges a standing side-on X-ray of the spine to measure the curve (the Cobb angle) and look for wedged vertebrae. MRI (magnetic resonance imaging) is used if there are nerve symptoms or before surgery. Pressure on the spinal cord is extremely rare, though 6 of 69 people having surgery had abnormal nerve signs, mostly mild, and rarely a progressing curve causes leg weakness, numbness, bladder or bowel changes or breathlessness.
Schmorl's nodes on their own are common in everyone: on MRI, 71% of men and 77% of women in a Japanese population study (average age about 66) had at least one, and so did 48% of 240 adult skeletons. 'Scheuermann's' on a lower-back report usually describes these common end-plate changes rather than the teenage rounded back: in a UK audit of 50 reports using the word, 80% described lower-back features, and only about half of GPs understood the term. In 188 Chinese hospital staff, 18.1% had a 'Scheuermann-like' lower spine on MRI; they had back pain no more often than others, though when they had it, it tended to be more severe.
Young athletes in sports that load the back often show these changes: in 142 elite young athletes, 36% to 55% had X-ray changes, which were linked with back pain. A report on its own doesn't explain pain or mean damage; the examination decides what it means for you.
Sources 1, 2, 14, 15, 6, 16, 17, 18, 19, 20
How it usually goesEmerging evidence
The curve can get worse while a teenager is still growing and usually stops when growth ends. Mild untreated curves can creep a little over decades: in 19 Finnish men, an average curve grew from 46 to 60 degrees over 46 years, without that predicting how well they managed.
Most people live normal lives. After an average of 32 years, 67 people with an average curve of 71 degrees had more intense back pain and less back extension than people without it, but no difference in days off work, everyday activities, self-esteem, social life or recreation, and lung function was normal unless the curve was over 100 degrees. Untreated, 49 Finnish adults had 2.5 times the odds of constant back pain at 37 years, unrelated to the size of the curve. In 943 Danish twins with it, physical quality of life was slightly lower (50.5 against 53.2 on a 100-point scale) and mental quality of life the same, and in 22 Finnish men in their 60s, constant back pain was commoner than in men without it.
Very large curves (over 75 degrees) reduced aerobic fitness on a treadmill test in 41 teenagers. A review says that under 60 degrees, symptoms usually settle into adulthood with conservative care, though some adults keep more back pain than average. In a support group's registry of 168 people, 63.1% reported severe pain, but people who join such registries aren't typical.
Sources 1, 6, 21, 22, 23, 24, 25, 26, 27, 28
