What causes the progression of scoliosis in one's early 20s?

See below. Scoliosis (a curvature of the spine to the side) often begins around 10 years old;it’s 4-5 times more common in girls than boys. It usually causes no symptoms, but if severe, it can compress the lungs. Because it can continue to progress as long as the spine is growing, your doctor will recheck it regularly. If the curve gets to 20+ degrees, your doctor can recommend an orthopedist.