In most cases, the cause of scoliosis is not known. This is called idiopathic scoliosis. It develops mostly in children and teens and appears to be related to several things, including genetics, as it often runs in families.
There are two types of scoliosis: nonstructural and structural.
Structural scoliosis involves a curve in the spine, with rotation, that is irreversible and is usually caused by an unknown factor (idiopathic) or a disease or condition such as:
Disorders that were present at birth (congenital), such as spina bifida, in which the spinal canal does not close properly; or a disorder that affects the formation of bones. These curves can be harder to correct. They often get worse as the child grows, especially during the teen years.