Scoliosis affects people of every age, sex, and background, but certain groups face significantly higher risk. The global prevalence in children and adolescents is about 1.65%, based on a meta-analysis of over 42 million young people across 33 countries. In older adults, rates climb dramatically, with some studies finding curvature in more than 60% of elderly volunteers.
Children and Adolescents: The Largest Group
The most common form of scoliosis, adolescent idiopathic scoliosis (AIS), develops between ages 10 and 18. “Idiopathic” means there’s no identifiable cause, and this type accounts for the majority of pediatric cases. A spinal curve must measure at least 10 degrees on an X-ray to qualify as scoliosis. Many mild curves never progress and may go unnoticed without screening.
Major medical organizations in the U.S., including the American Academy of Pediatrics and the American Academy of Orthopaedic Surgeons, recommend screening girls at ages 10 and 12, and boys once at age 13 or 14. The timing reflects the different growth spurts in each sex. Screening typically involves a forward bend test and a simple measuring tool called a scoliometer.
Girls Are Affected More Often and More Severely
Scoliosis occurs in both sexes, but girls are diagnosed roughly twice as often as boys overall. That gap widens sharply when you look at more severe curves. For mild curves between 10 and 20 degrees, the female-to-male ratio is about 1.4 to 1. For curves exceeding 40 degrees, the ratio jumps to 7.2 to 1. At curves above 30 degrees, some studies report ratios as high as 10 to 1.
This means that while boys and girls develop small curves at somewhat similar rates, girls are far more likely to see those curves worsen into ranges that require bracing or surgery. The reasons aren’t fully understood, but the pattern is consistent across decades of research.
Growth Potential Determines Who Gets Worse
Not every child diagnosed with scoliosis will see their curve progress. The strongest predictor of worsening is how much growing a child has left to do. Doctors assess skeletal maturity using several markers, including chronological age, the stage of pelvic bone development (known as the Risser stage), and, in girls, time since their first period.
A child diagnosed at age 10 with significant growth remaining faces a higher risk of progression than a 16-year-old with the same curve. Importantly, spinal growth continues even after other growth markers suggest a child is nearly done growing. Vertebral growth doesn’t fully stop until the final stage of pelvic bone maturation, which means some adolescents who appear nearly skeletally mature can still experience curve progression.
Adults Over 60: A Different Kind of Scoliosis
Many people don’t realize scoliosis can develop for the first time in middle age or later. Degenerative scoliosis, sometimes called “de novo” scoliosis, occurs in a previously straight spine as the discs and joints wear down unevenly over time. Prevalence in the adult population ranges from 2% to 32% depending on the study, and in elderly populations, it can exceed 60%.
The underlying process involves asymmetric breakdown of the spinal discs and the small joints connecting vertebrae. When one side deteriorates faster than the other, it creates uneven loading that gradually pulls the spine into a curve. Osteoporosis accelerates this process, particularly in postmenopausal women, because weakened vertebrae are more susceptible to asymmetric compression fractures. This makes older women especially vulnerable to both developing and worsening degenerative scoliosis.
Family History Raises Your Risk
Scoliosis runs in families, though it doesn’t follow a simple one-gene inheritance pattern. If you have a first-degree relative (parent or sibling) with scoliosis, your risk is about 11%, compared to roughly 2% or less in the general population. Sibling studies show that 19% of siblings develop curves of at least 10 degrees, and 11.5% develop curves of 20 degrees or more.
Risk drops off with distance in the family tree: second-degree relatives face about a 2.4% risk, and third-degree relatives about 1.4%. These numbers make scoliosis a “complex” genetic condition, meaning multiple genes likely contribute alongside environmental and developmental factors.
Scoliosis Linked to Neuromuscular Conditions
Children with conditions affecting the nervous system or muscles are at high risk for a distinct type called neuromuscular scoliosis. This develops because the muscles supporting the spine can’t maintain even tension, allowing the spine to curve. Conditions commonly associated with neuromuscular scoliosis include cerebral palsy, Duchenne muscular dystrophy, spinal muscular atrophy, spina bifida, and paralysis.
Neuromuscular scoliosis tends to behave differently from idiopathic scoliosis. Curves often progress more quickly, are more likely to continue worsening after skeletal maturity, and frequently involve longer sections of the spine. Children with these underlying conditions are typically monitored for spinal curvature as part of their ongoing care.
Congenital Scoliosis: Present From Birth
A small number of children are born with vertebrae that didn’t form correctly during early pregnancy. Congenital scoliosis occurs in roughly 0.5 to 1 per 1,000 live births and accounts for about 10% of all pediatric scoliosis cases. Some screening studies using incidental imaging suggest the true rate may be closer to 1.8 per 1,000.
What makes congenital scoliosis particularly important to identify early is that 60 to 70% of affected children also have abnormalities in other organ systems. The genitourinary system is involved in 20 to 30% of cases, with issues like missing or malformed kidneys. Cardiovascular abnormalities appear in 10 to 15%, and central nervous system anomalies in 15 to 20%. Because of this overlap, a diagnosis of congenital scoliosis usually triggers a broader workup including heart and kidney imaging.
Racial and Ethnic Disparities
Scoliosis occurs across all racial and ethnic groups, but research suggests differences in severity and access to care. Data from a large U.S. scoliosis registry found that Black patients had the second-highest average curve severity at the time of surgery, and one study found that race had a greater impact on disease severity than socioeconomic status. Native American patients in the registry had the highest average pre-surgical curve measurements, though the sample size was very small.
Hispanic, Black, Asian, and Native American children were all underrepresented in the registry compared to their share of the U.S. pediatric population, raising concerns about unequal access to early detection and treatment. When scoliosis is caught later or followed up less consistently, curves have more time to progress before intervention.