Scoliosis is an abnormal sideways curve in your spine

Scoliosis means your spine curves to the side instead of running straight down the middle of your back. A healthy spine has a gentle forward curve in the neck and lower back, and a gentle backward curve in the mid-back. Scoliosis adds a sideways S-shape or C-shape curve on top of those normal curves. The curve can happen on the right side or the left side, and it can be mild enough that you don't notice it, or severe enough to change your posture and affect how your organs sit in your chest.

The sideways curve is what makes scoliosis different from other spine problems. It is not the same as poor posture, which you can correct by sitting or standing differently. Scoliosis is a structural change in the bones of your spine itself. The vertebrae—the small bones stacked on top of each other that make up your spine—are actually rotated or tilted, not just bent.

Key Takeaways

  • Scoliosis is a sideways curve in the spine that is measured in degrees; curves under 25 degrees are usually watched rather than treated, while curves over 50 degrees often need surgery.
  • The three main types are idiopathic (no known cause, most common in teens), congenital (present from birth due to bone formation problems), and neuromuscular (caused by conditions like cerebral palsy or muscular dystrophy).
  • Doctors use X-rays and a measurement called the Cobb angle to determine how severe the curve is and whether it is likely to get worse.
  • Many people with mild scoliosis have no symptoms and discover it by accident during an X-ray for another reason.
  • Severe scoliosis can affect breathing and heart function because the curved spine takes up space that the lungs and heart need.

How doctors measure the curve

Doctors measure scoliosis using an X-ray and a method called the Cobb angle. The Cobb angle is the angle formed between two lines drawn on the X-ray—one along the top of the most tilted vertebra at the top of the curve, and one along the bottom of the most tilted vertebra at the bottom of the curve. The angle between those lines, measured in degrees, tells the doctor how severe the curve is.

The measurement matters because it predicts what will happen next. A curve under 10 degrees is considered normal variation. A curve between 10 and 25 degrees is mild scoliosis and usually does not need treatment beyond monitoring. A curve between 25 and 40 degrees is moderate, and a doctor may recommend a brace if you are still growing. A curve over 40 to 50 degrees is severe and often leads to surgery, because curves that large tend to keep getting worse and can interfere with heart and lung function.

The curve can change over time, especially in children and teenagers whose spines are still growing. That is why doctors take repeat X-rays at regular intervals—sometimes every 4 to 6 months—to see whether the curve is staying the same, getting better, or getting worse.

The three main types of scoliosis

Idiopathic scoliosis is scoliosis with no known cause. It accounts for about 80 percent of all scoliosis cases. It usually shows up in teenagers, more often in girls than boys, though it can appear in younger children or adults. Doctors do not know why it happens, but it tends to run in families, so genetics play a role. Idiopathic scoliosis is not caused by poor posture, carrying a heavy backpack, or sports.

Congenital scoliosis is present from birth. It happens when the vertebrae do not form correctly in the womb. Some vertebrae may be wedge-shaped instead of rectangular, or two vertebrae may be fused together. Congenital scoliosis is often discovered in infancy or early childhood, sometimes during a routine newborn exam or when a parent notices the baby's spine looks curved. It may be associated with other birth differences in the heart, kidneys, or other organs.

Neuromuscular scoliosis develops as a result of a condition that affects the nerves or muscles, such as cerebral palsy, muscular dystrophy, spina bifida, or Down syndrome. The weak or unbalanced muscles cannot hold the spine straight, so it curves. Neuromuscular scoliosis often appears later in childhood or adolescence as the underlying condition progresses, and it tends to be more severe and progress faster than idiopathic scoliosis.

Why some curves get worse and others stay the same

The biggest factor in whether a curve will progress is age and skeletal maturity. Children and teenagers whose bones are still growing are at much higher risk of progression. A curve that is 25 degrees in a 10-year-old is more likely to get worse than the same curve in a 16-year-old, because the younger child has more growing left to do. Once a person stops growing—usually by the late teens or early twenties—the curve tends to stabilize.

The size of the curve also matters. Larger curves are more likely to progress. A curve of 50 degrees is more likely to keep growing than a curve of 20 degrees. The location of the curve in the spine makes a difference too. Curves in the mid-back (thoracic spine) tend to progress more than curves in the lower back (lumbar spine).

Girls are more likely than boys to have progression, especially during puberty when growth accelerates. Family history also plays a role—if a parent or sibling had scoliosis that progressed, the risk is higher. Doctors use all of these factors together to decide whether to monitor a curve or recommend treatment.

What scoliosis feels like and what it does not

Many people with mild to moderate scoliosis have no symptoms at all. They may not know they have it until a doctor finds it on an X-ray taken for a different reason, or until someone notices their shoulders or hips look uneven. Mild scoliosis does not cause pain in children or teenagers, though some adults with long-standing curves report back discomfort, especially after standing or sitting for long periods.

Severe scoliosis can cause visible changes: one shoulder higher than the other, one hip higher than the other, ribs that stick out more on one side, or a noticeable lean to one side. In severe cases, the curve can reduce the space in the chest, which can make it harder to breathe or put pressure on the heart. Some people with severe scoliosis report fatigue or shortness of breath with activity.

Scoliosis does not cause poor grades, behavioral problems, or learning disabilities. It is not contagious. It is not caused by carrying a heavy backpack, playing sports, or slouching, though poor posture can make a curved spine look more pronounced.

How scoliosis is found

Scoliosis is often discovered during a school screening, where a nurse or doctor looks at children's spines by having them bend forward. A forward bend makes a curve more visible because the ribs on the curved side stick out. If the screening suggests scoliosis, the child is referred to a doctor for an X-ray to confirm the diagnosis and measure the curve.

Scoliosis can also be found when a parent or doctor notices uneven shoulders or hips, or when an X-ray taken for another reason shows a curve. In adults, scoliosis may be discovered during imaging done for back pain or other spine problems. Congenital scoliosis is sometimes found on prenatal ultrasound or during a newborn exam.

Once scoliosis is found, a doctor—usually an orthopedic surgeon or spine specialist—will take a detailed history, do a physical exam, and order X-rays to measure the curve and determine the type. The doctor will also ask about family history, because idiopathic scoliosis runs in families.

What happens after diagnosis

The plan depends on the size of the curve, the person's age and growth potential, the type of scoliosis, and how fast the curve is progressing. For mild curves in children who are still growing, the doctor usually recommends monitoring with X-rays every 4 to 6 months to watch for progression. For moderate curves in growing children, a brace may be recommended to try to prevent the curve from getting worse. For severe curves or curves that are progressing rapidly, surgery may be discussed.

In adults whose spines have stopped growing, mild to moderate curves that are not causing symptoms are usually monitored but not treated. If an adult develops pain or the curve is progressing, treatment options may be considered. The goal of treatment is to prevent progression, reduce pain if present, and in severe cases, prevent complications like breathing problems.

Frequently Asked Questions

Can scoliosis go away on its own?

No. Once the spine develops a curve, it does not straighten on its own. In children and teenagers, the curve may stay the same or get worse as they grow. In adults, mild curves usually stay stable. Treatment aims to prevent progression or manage symptoms, not to cure the curve.

Is scoliosis painful?

Mild to moderate scoliosis usually causes no pain, especially in children and teenagers. Some adults with long-standing curves report back discomfort. Severe scoliosis can cause pain or breathing problems, but pain is not the main reason for treatment—progression and potential organ effects are.

Can exercise or physical therapy fix scoliosis?

Exercise and physical therapy cannot straighten a curved spine, but they can strengthen the muscles around the spine and may help with posture and comfort. They are often used alongside bracing or after surgery, but they are not a substitute for bracing or surgery when those are needed.

Does scoliosis run in families?

Idiopathic scoliosis, the most common type, does tend to run in families. If a parent or sibling has scoliosis, the risk is higher. However, not everyone with a family history develops scoliosis, and some people develop it with no family history.

Can I play sports if I have scoliosis?

Most people with scoliosis can play sports and stay active. Scoliosis is not caused by sports, and activity does not make it worse. A doctor or physical therapist can advise on any modifications if needed, but scoliosis alone is not a reason to stop playing sports.