Idiopathic Scoliosis
This is the most common type of scoliosis, and constitutes 80% of the cases of scoliosis.

Idiopathic = exact cause not known.  It is subdivided into 3 categories:
1) Infantile Scoliosis: birth to 3 years old
2) Juvenile Scoliosis: 3 - 10 years old
3) Adolescent Scoliosis: 10 -18 years old

4) Adult Scoliosis 18<
 
Congenital Scoliosis

This is a rare type of scoliosis, often due to failures of formation or segmentation of the spine.  People with congenital scoliosis will develop lateral spinal curves in infancy.
 
Neuromuscular Scoliosis
In this type of scoliosis, a lateral curvature of the spine occurs due to muscular weakness or neurological disorders.
 
Degenerative Scoliosis
Degenerative scoliosis occurs in adults and is due to degeneration of the spine that occurs with prolonged asymmetric loading, loss or lumbar lordosis and signs show up in older patients.