Scoliosis: Symptoms, Causes & Treatment Options

What Is Scoliosis?

Scoliosis is a three-dimensional deformity of the spine where the vertebral column curves sideways and rotates. The curve typically forms a C-shape or S-shape when viewed from behind. While mild curves often cause no symptoms, more severe curvature can affect appearance, cause back pain, and in rare cases impact heart and lung function.

The human spine naturally curves from front to back, creating the gentle S-shape visible from the side that helps distribute body weight and absorb shock. In scoliosis, however, the spine develops an abnormal lateral (sideways) curve, often accompanied by rotation of the vertebrae. This rotation is what causes the characteristic "rib hump" that becomes visible when a person with scoliosis bends forward.

Scoliosis is not simply poor posture or a result of carrying heavy objects. It is a structural change in the spine that cannot be corrected by standing up straight or changing habits. The condition exists on a spectrum from very mild curves that are barely noticeable to severe deformities that can significantly impact quality of life. Medical professionals measure the severity of scoliosis using the Cobb angle, which calculates the degree of curvature on an X-ray image.

Understanding scoliosis requires recognizing that it affects people differently depending on factors such as the location of the curve, the age of onset, the underlying cause, and whether the person is still growing. A 20-degree curve in a 10-year-old with several years of growth remaining presents different considerations than the same curve in a fully mature adult.

How Common Is Scoliosis?

Scoliosis affects approximately 2-3% of adolescents worldwide, making it one of the most common spinal conditions in young people. However, the majority of these cases are mild and require no treatment beyond observation. Only about 0.3-0.5% of the population has curves severe enough to warrant intervention with bracing or surgery.

The condition shows a notable gender difference. While small curves occur equally in boys and girls, moderate and severe curves requiring treatment are significantly more common in females. Girls are approximately 8 times more likely than boys to have curves that progress and require treatment. This disparity is not fully understood but may relate to hormonal factors and differences in growth patterns.

Scoliosis can develop at any age, but the most common form—adolescent idiopathic scoliosis—typically appears between ages 10 and 15, coinciding with the pubertal growth spurt. During this period of rapid growth, existing curves may progress quickly, which is why regular monitoring during adolescence is so important.

What Causes Scoliosis?

In approximately 80% of cases, scoliosis has no identifiable cause and is termed "idiopathic." Research suggests genetic factors play a significant role, as scoliosis often runs in families. The remaining 20% of cases result from congenital spine abnormalities, neuromuscular conditions, degenerative changes, or other underlying medical conditions.

Despite decades of research, the exact mechanisms that cause idiopathic scoliosis remain unclear. Scientists have identified multiple genetic markers associated with the condition, suggesting that inherited factors influence who develops scoliosis and whether curves progress. Studies of identical twins show that if one twin has scoliosis, the other has an approximately 73% chance of also developing it, strongly supporting a genetic component.

Current research explores several theories about what triggers curve development and progression. These include abnormalities in the growth plates of vertebrae, differences in spinal cord tension, hormonal imbalances affecting bone growth, and variations in how the brain processes balance and postural information. It's likely that idiopathic scoliosis results from a combination of these factors rather than a single cause.

Importantly, there are several myths about scoliosis causes that should be dispelled. Scoliosis is NOT caused by: carrying heavy backpacks, poor posture, sleeping positions, participation in sports, or lack of calcium in the diet. These factors do not cause structural changes to the spine that characterize scoliosis.

Types of Scoliosis by Cause

Medical professionals classify scoliosis into several categories based on the underlying cause, which is important because different types may require different treatment approaches and have different prognoses.

Neuromuscular Scoliosis

Neuromuscular scoliosis develops as a secondary condition in people with underlying neurological or muscular disorders. Conditions commonly associated with this type of scoliosis include cerebral palsy, muscular dystrophy, spinal muscular atrophy, and spina bifida. In these cases, weakness or imbalance in the muscles supporting the spine leads to curvature.

This type of scoliosis often progresses more rapidly and to greater severity than idiopathic scoliosis. The curves may also continue to progress even after skeletal maturity, unlike idiopathic curves which typically stabilize when growth is complete. Treatment approaches may differ, and decisions often need to consider the overall health status and capabilities of the individual.

Functional vs. Structural Scoliosis

It's important to distinguish between structural scoliosis and functional (non-structural) scoliosis. Structural scoliosis involves a fixed curvature of the spine that doesn't straighten when the person bends to the side or lies down. Functional scoliosis, in contrast, is a reversible curve caused by factors outside the spine, such as leg length differences or muscle spasms.

Functional scoliosis typically resolves when the underlying cause is addressed. For example, if a leg length discrepancy is causing the pelvis to tilt and the spine to curve in compensation, a shoe lift may correct the imbalance and eliminate the apparent scoliosis. This is quite different from structural scoliosis, which requires different management approaches.

What Are the Symptoms of Scoliosis?

The most visible symptoms of scoliosis include uneven shoulders, one shoulder blade protruding more than the other, an asymmetrical waistline, one hip appearing higher, and a visible rib prominence when bending forward. Most adolescents with scoliosis experience no pain, though adults may develop back discomfort and fatigue.

Scoliosis often develops gradually and without pain, which is why it can go unnoticed until the curve becomes more pronounced. Parents may first notice something is different when their child's clothes don't hang evenly, or when one shoulder strap consistently slips off. School screening programs have historically been valuable in detecting scoliosis early, though they are no longer universal in all regions.

The visible signs of scoliosis result from the spine's sideways curvature and rotation. When the spine curves and rotates, it pulls the attached ribs along with it. On one side of the back, this pushes the ribs backward, creating a prominence. On the other side, the ribs are pulled forward, creating an apparent flattening. This asymmetry becomes most visible during the forward bend test, when one side of the back appears higher than the other.

The severity of visible changes doesn't always correlate directly with the degree of curvature. A 30-degree curve in one person might appear quite different from the same degree curve in another, depending on factors like body type, curve location, and the amount of rotation present.

Physical Signs to Watch For

• Uneven shoulders: One shoulder sits higher than the other when standing straight
• Prominent shoulder blade: One shoulder blade sticks out more visibly than the other
• Asymmetric waist: The space between the arm and body appears different on each side
• Uneven hips: One hip appears higher or more prominent than the other
• Rib hump: A noticeable bulge on one side of the back when bending forward
• Head not centered: The head appears to tilt or sit off-center over the pelvis
• Uneven leg length appearance: Though actual leg lengths may be equal

When Does Scoliosis Cause Pain?

A common misconception is that scoliosis always causes back pain. In reality, most adolescents with idiopathic scoliosis experience little to no discomfort. Pain in a child or adolescent with scoliosis warrants further investigation, as it may indicate an underlying condition such as a tumor, infection, or other spinal abnormality rather than the scoliosis itself.

Adults with scoliosis, however, are more likely to experience back pain and fatigue. This is partly due to the asymmetric loading of the spine and the degenerative changes that can develop over time in a curved spine. Adults with scoliosis may also develop stenosis (narrowing of the spinal canal) more readily than those without curvature, which can cause leg pain and weakness.

When scoliosis does cause discomfort, it typically manifests as muscle fatigue and soreness rather than sharp pain. The muscles on one side of the spine work harder to support the curved structure, leading to asymmetric muscle development and fatigue. Some people notice increased discomfort after prolonged standing or sitting in one position.

Can Scoliosis Cause Breathing Problems?

In severe cases, scoliosis can affect lung function. When the thoracic (upper) spine curves significantly—typically beyond 70-80 degrees—the rotation and deformity can restrict the chest cavity and limit lung expansion. This is relatively rare and occurs primarily in untreated severe scoliosis or in neuromuscular scoliosis where curves may progress to extreme degrees.

For the vast majority of people with scoliosis, including those with moderate curves, lung function remains normal. Even athletes with scoliosis typically perform at the same level as their peers without the condition. Research has shown that mild to moderate scoliosis does not significantly impact cardiovascular or respiratory fitness.

How Is Scoliosis Diagnosed?

Scoliosis is diagnosed through physical examination and confirmed with X-rays. The Adam's forward bend test is used for screening, where asymmetry indicates possible scoliosis. X-rays measure the Cobb angle—the degree of curvature—which determines severity. MRI may be ordered to rule out underlying conditions in atypical cases.

The diagnostic process for scoliosis typically begins with a physical examination. A healthcare provider will ask about family history, recent growth, and any symptoms. They will examine the patient's back while standing, looking for the visual signs described earlier: uneven shoulders, asymmetric waistline, and prominent hip or shoulder blade.

The most important clinical test is the Adam's forward bend test. The patient bends forward at the waist with arms hanging down and palms together while the examiner views the back from behind. This position makes any rotation of the spine apparent—a rib hump or lumbar prominence on one side indicates likely scoliosis. Healthcare providers may use a device called a scoliometer to measure the degree of trunk rotation during this test. A rotation of 7 degrees or more typically warrants X-ray evaluation.

If the physical examination suggests scoliosis, standing X-rays of the entire spine are taken. These images allow precise measurement of the curve using the Cobb angle method. The Cobb angle is calculated by drawing lines along the most tilted vertebrae at the top and bottom of the curve; the angle where these lines intersect gives the curve measurement in degrees.

Understanding Cobb Angle Measurements

The Cobb angle is the standard measurement used worldwide to describe scoliosis severity and guide treatment decisions. Understanding what these numbers mean helps patients and families participate more effectively in care decisions.

When Is MRI Needed?

Not every patient with scoliosis needs an MRI. X-rays are usually sufficient for diagnosis and monitoring of typical idiopathic scoliosis. However, MRI may be recommended in certain situations to rule out underlying conditions that could be causing the curvature:

• Atypical curve patterns: Left thoracic curves (typical curves are right thoracic) or unusual curve shapes
• Very young onset: Scoliosis developing before age 10
• Rapid progression: Curves that worsen quickly
• Neurological symptoms: Numbness, weakness, or changes in reflexes
• Pain as a primary symptom: Especially in children
• Pre-surgical planning: Before any operative intervention

The MRI can reveal spinal cord abnormalities such as syringomyelia (a fluid-filled cavity in the spinal cord), tethered cord, or tumors that might be causing or contributing to the scoliosis. Identifying these conditions is essential as they may require treatment before or instead of scoliosis-specific interventions.

When Should You See a Doctor for Scoliosis?

Seek medical evaluation if you notice uneven shoulders, a prominent shoulder blade, asymmetric waistline, or any visible spinal curvature. During adolescence, have scoliosis monitored every 4-6 months during growth periods. Adults should seek care for new or worsening back pain, changes in posture, or neurological symptoms like leg numbness.

Early detection of scoliosis provides the greatest opportunity for non-surgical management. While mild curves may never require intervention, identifying moderate curves early—while significant growth remains—allows for bracing, which has been proven effective in preventing progression. This window of opportunity is limited to the growing years.

Parents should consider having their children evaluated if they notice any of the visual signs mentioned earlier. School screening programs, where they exist, can be helpful, but many regions have discontinued routine scoliosis screening. A primary care physician or pediatrician can perform initial screening and refer to an orthopedic specialist if needed.

For adolescents already diagnosed with scoliosis, regular monitoring during growth is essential. The frequency of follow-up depends on the curve size and growth remaining. Patients are typically seen every 4-6 months during periods of rapid growth, with the interval potentially extending as growth slows. The goal is to detect any progression early enough to intervene if necessary.

How Is Scoliosis Treated?

Treatment depends on curve severity, skeletal maturity, and progression risk. Options include observation for mild curves, bracing for moderate curves in growing children (72% success rate when worn as prescribed), physiotherapy-specific exercises, and spinal fusion surgery for severe or rapidly progressing curves. Treatment is individualized based on multiple factors.

The goal of scoliosis treatment is to prevent curve progression, maintain or improve function, and address any symptoms. Treatment decisions consider multiple factors: the degree of curvature, the location and pattern of the curve, how much growth remains, whether the curve is progressing, the presence of any symptoms, and the patient's preferences and lifestyle.

For many people with scoliosis, active treatment beyond observation is not necessary. Mild curves that are stable and not causing symptoms may only need periodic monitoring to ensure they don't progress. This is particularly true for adults, whose curves are unlikely to change significantly once skeletal maturity is reached.

The treatment approach differs significantly between growing children and adults. In children, the focus is on preventing progression during the remaining growth period. In adults, treatment primarily addresses symptoms such as pain and functional limitations, since adult curves progress slowly if at all.

Observation and Monitoring

For curves under 25 degrees, observation is typically the recommended approach. This involves regular clinical examinations and periodic X-rays to monitor for any progression. The frequency of monitoring depends on the amount of growth remaining and how close the curve is to the threshold for intervention.

During observation, patients can continue all normal activities including sports and exercise. There are no restrictions on physical activity for most people with scoliosis. In fact, staying active and maintaining strong core and back muscles is encouraged.

Bracing for Adolescent Scoliosis

Bracing is the primary non-surgical treatment for moderate scoliosis (typically 25-40 degrees) in growing adolescents. The landmark BrAIST study published in the New England Journal of Medicine demonstrated that bracing is effective: patients who wore their brace as prescribed had a 72% success rate in preventing curve progression to surgical threshold, compared to 48% in those who only observed.

Braces work by applying external pressure to guide spinal growth in a straighter direction. They do not correct existing curvature but aim to prevent worsening during growth. The effectiveness of bracing depends heavily on compliance—the more hours per day the brace is worn, the better the outcomes. Most protocols recommend wearing the brace 16-23 hours per day.

Several types of braces exist, each with different designs and wearing schedules:

• Boston brace: The most common type; a thoraco-lumbo-sacral orthosis (TLSO) worn under clothing
• Wilmington brace: Custom-molded TLSO similar to the Boston brace
• Charleston bending brace: Worn only at night; bends the patient toward the curve
• Milwaukee brace: A full-torso brace with neck ring; used less commonly today
• Rigo-Chêneau brace: A European design with asymmetric correction zones

The psychological impact of bracing should not be underestimated. Wearing a brace during adolescence can be challenging, affecting body image and social interactions. Support from family, healthcare providers, and peer support groups can help adolescents cope with brace wear. Modern braces are designed to be less visible under clothing and more comfortable than older designs.

Physical Therapy and Exercise

Physiotherapy-specific scoliosis exercises (PSSE) are specialized exercise programs designed specifically for scoliosis. The best-studied approach is the Schroth method, developed in Germany and now used worldwide. These exercises aim to improve posture, reduce asymmetric loading, strengthen muscles, and potentially slow curve progression.

Unlike general exercise, PSSE programs are customized to the individual's curve pattern and teach specific breathing techniques and postural corrections. Studies suggest that PSSE may help reduce curve progression and improve quality of life, though the evidence is still evolving. The SOSORT guidelines recommend PSSE as part of a comprehensive treatment approach, particularly for moderate curves.

General physical activity and sports are encouraged for people with scoliosis. There is no evidence that sports participation worsens scoliosis or that avoiding activity helps. Activities that strengthen the core and back muscles—swimming, yoga, Pilates—may be particularly beneficial. Contact sports and activities with spinal loading (like gymnastics and weightlifting) are generally safe, though individual guidance from a healthcare provider is recommended.

Surgical Treatment

Surgery for scoliosis is typically considered when curves exceed 40-50 degrees, when curves progress rapidly despite bracing, or when significant pain or functional limitation is present. The decision for surgery weighs the risks of the procedure against the risks of leaving a severe curve untreated.

The standard surgical approach is spinal fusion. This procedure involves correcting the curve as much as safely possible, then fusing the vertebrae together with metal rods, screws, and bone grafts. The fusion permanently straightens the treated portion of the spine, trading some flexibility for stability and correction.

Modern surgical techniques have significantly improved outcomes compared to earlier approaches. Surgeons now use pedicle screws that allow three-dimensional correction, and computer-assisted navigation improves accuracy and safety. Most patients achieve 50-70% correction of their curve with surgery.

Recovery from spinal fusion typically involves a hospital stay of 3-5 days, followed by several weeks of limited activity. Most patients return to school within 4-6 weeks and can resume most activities within 6-12 months. There is some permanent loss of spinal flexibility in the fused segments, though most patients adapt well and can participate in most activities including many sports.

Treatment for Very Young Children

Scoliosis in infants and young children (infantile and juvenile scoliosis) presents unique challenges. Because these children have many years of growth ahead, early intervention is important to prevent severe progression, but the treatment options must account for ongoing growth.

For young children, serial casting may be used. This involves applying a plaster or fiberglass cast around the torso that gently corrects the curve. The cast is changed every 2-3 months as the child grows. This technique, known as Mehta casting, can be remarkably effective in young children, with some achieving complete or near-complete curve resolution.

Growing rod systems are a surgical option for young children with severe, progressive curves. These devices are attached to the spine and can be lengthened periodically—either through additional surgeries or magnetically from outside the body—to accommodate growth. The goal is to control the curve while allowing the spine and chest to continue developing.

What Is It Like Living with Scoliosis?

Most people with scoliosis lead full, active lives without significant limitations. Mild to moderate scoliosis typically doesn't interfere with daily activities, sports, pregnancy, or career choices. Some adults may develop back pain and fatigue that can be managed with exercise, physical therapy, and pain management strategies when needed.

The diagnosis of scoliosis can initially feel overwhelming, particularly for adolescents and their families. However, it's important to understand that scoliosis exists on a wide spectrum, and the majority of people with the condition experience minimal impact on their daily lives. Even those with moderate curves often participate fully in sports, careers, and family life.

Body image concerns are common, especially during adolescence. The visible asymmetry of scoliosis—uneven shoulders, rib prominence, or asymmetric waist—can affect self-confidence. Support from family, friends, and healthcare providers is valuable. Many people find it helpful to connect with others who have scoliosis through support groups or online communities.

Physical activity and exercise are not only safe but encouraged for people with scoliosis. There is no evidence that sports or physical activity worsens scoliosis, and the benefits of staying active far outweigh any theoretical risks. Many elite athletes have competed at the highest levels despite having scoliosis, including Olympic gold medalist Usain Bolt.

Scoliosis and Pregnancy

Women with scoliosis can generally have healthy pregnancies and deliveries. Research shows that pregnancy does not significantly worsen scoliosis curves, even in women with moderate to severe curvature. The additional weight and postural changes of pregnancy may cause some temporary increase in back discomfort, but this typically resolves after delivery.

Epidural anesthesia for labor is generally possible for women with scoliosis, though the procedure may be more technically challenging depending on the curve. Women who have had spinal fusion surgery should discuss anesthesia options with their healthcare team well before delivery. In most cases, cesarean delivery is not necessary solely due to scoliosis.

Long-term Outlook

The long-term prognosis for scoliosis depends largely on the curve severity and whether treatment was received during the growing years. Mild curves (under 30 degrees) at skeletal maturity typically remain stable throughout adult life and rarely cause significant problems. Moderate curves (30-50 degrees) may progress slowly over decades, potentially gaining 1-2 degrees per year, though many remain stable.

Severe untreated curves have a higher likelihood of progression in adulthood and greater risk of developing symptoms. This is why early detection and appropriate treatment during adolescence is emphasized—preventing progression to severe curvature provides the best long-term outcomes.

Adults with scoliosis may be more prone to developing degenerative changes in the spine, including disc degeneration and arthritis. This can lead to back pain and, in some cases, spinal stenosis. However, these changes develop gradually over many years and can often be managed with conservative measures including exercise, physical therapy, and pain management.