If you look at someone’s back, you’ll see that the spine runs straight down the middle. When a person has scoliosis, their backbone curves to the side.

The angle of the curve may be small, large or somewhere in between. But anything that measures more than 10 degrees is considered scoliosis. Doctors may use the letters “C” and “S” to describe the curve of the backbone.

You probably don’t look directly at too many spines, but what you might notice about someone with scoliosis is the way they stand. They may lean a little or have shoulders or hips that look uneven.