We all have curves in our spines, but scoliosis causes the spine to curve in the wrong direction. It causes sideways curves, and those are different from the spine's normal curves. If you looked at your spine from the side, you'd see it curves out at your neck (cervical spine), in at your mid-back (thoracic spine), and out again at your low back (lumbar spine). Your back is supposed to curve that way.
However, if you looked at your spine from behind, you shouldn't see any curves. When there are sideways curves in the spine from the rear view, that's scoliosis. The curves can look like an "S" or a "C."
Spine Anatomy: Quick Lesson
To understand scoliosis, you first need to know what a healthy spine looks like. There are four regions in your spine:
- Cervical spine: This is your neck, which begins at the base of your skull. It contains seven small spinal bones (called vertebrae), which doctors label C1 to C7 (the "C" means cervical). The numbers one to seven indicate the level of the vertebrae. C1 is closest to your skull, while C7 is closest to your chest.
- Thoracic spine: Your mid-back has 12 vertebrae that are labeled T1 to T12 (the "T" means thoracic). Vertebrae in your thoracic spine connect to your ribs, making this part of your spine relatively stiff and stable. Your thoracic spine doesn't move as much as the other regions of your spine.
- Lumbar spine: In your low back, you have five vertebrae that are labeled L1 to L5 (the "L" means lumbar). These vertebrae are your largest and strongest vertebrae, responsible for carrying a lot of your body's weight. The lumbar vertebrae are also your last "true" vertebrae; down from this region, your vertebrae are fused. In fact, L5 may even be fused with part of your sacrum.
- Sacrum and coccyx: The sacrum has five vertebrae that usually fuse by adulthood to form one bone. The coccyx—commonly known as your tail bone—has four (but sometimes five) fused vertebrae.
Normal Spinal Curves: Lordosis and Kyphosis
When viewed from the side, you can see the spine has both inward and outward curves. These curves help your back carry your weight and are also important for flexibility.
There are two types of normal curves in your spine, and they are called kyphosis and lordosis. Kyphosis means the spine curves inward, and lordosis means the spine curves outward.
There are two kyphotic and two lordotic spinal curves in a normal spine. Your cervical and lumbar spines each have a lordotic curve. Your thoracic spine and sacrum have kyphotic curves.
While kyphosis and lordosis refer to a healthy curvature in your spine, they also describe abnormal spinal curves that are different than scoliosis. Abnormal lordosis is an extreme inward spinal curve. Abnormal kyphosis is a condition that results in a hunchback or slouching posture, and you can read about it in our Kyphosis Center.
Types of Scoliosis
Scoliosis is generally associated with children, but adults can have it, too. This typically happens when scoliosis is not detected during childhood or the disease progresses aggressively. Most cases of scoliosis—more than 80%, in fact—are idiopathic, meaning they don’t have a known cause.
Below are the different types of scoliosis:
- Infantile idiopathic scoliosis is diagnosed in children ages 0 to 3.
- Congenital scoliosis occurs when the spine does not develop properly in the womb.
- Neuromuscular scoliosis is caused by brain, spinal cord, and muscular system disorders.
- Syndromic scoliosis develops as part of an underlying syndrome or disorder.
- Juvenile idiopathic scoliosis is diagnosed in children ages 4 to 10.
- Adolescent idiopathic scoliosis is diagnosed in young people ages 11 to 18.
- Adult idiopathic or degenerative scoliosis is diagnosed in people older than 18.
In addition to the types noted above, your spine specialist may refer to your scoliosis as early-onset scoliosis—a term for scoliosis detected before 10 years of age. Infantile idiopathic scoliosis, congenital scoliosis, neuromuscular scoliosis, syndromic scoliosis, and juvenile idiopathic scoliosis may all be considered early-onset scoliosis.
Scoliosis brings up images of braces and perhaps memories of being tested for it in grade school by the school nurse. Bracing is one of the most common treatment options for scoliosis because it may fix the curve without spine surgery.
Sometimes, though, the curve is too extreme and bracing doesn't help enough. In that situation, you can have scoliosis surgery to correct the curve. You can learn more about surgical treatment for scoliosis in scoliosis surgery for adults and scoliosis surgery for children.
For children, especially, it can be frightening to learn they have scoliosis. Having that label makes them different at a time in their lives when they don't want to be all that different. They might not like the idea of wearing a brace, either. But scoliosis is nothing to be scared or ashamed of. With the proper treatment, scoliosis doesn't have to define your life.