Scoliosis causes a sideways curve of your backbone, or spine. These curves are often S- or C-shaped. Scoliosis is most common in late childhood and the early teens, when children grow fast. Girls are more likely to have it than boys. It can run in families. Symptoms include leaning to one side and having uneven shoulders and hips. Sometimes the curve is temporary. It might be due to muscle spasms, inflammation or having different leg lengths. A birth defect, tumor or another disease might cause the spine to have a curve that isn't temporary. People with mild scoliosis might only need checkups to see if the curve is getting worse. Others might need to wear a brace or have surgery.