what symptoms can scolliosis cause?

Is it possible that someone is suffering from scoliosis and not knowing it? What symptoms scoliosis can cause? I am suspicious that my son has scoliosis. He look normal, but sometimes it seems to me like his left shoulder is little lower that right. He is 11 years old.

When you look at a person's spine from the front or back, it appears straight, but when a person has scoliosis, the spine typically curves out to one side and then back again. Or, has two bowed-out areas that balance each other, resembling an S shape. Physical symptoms that scoliosis causes are that you can see are exactly when one shoulder appears lower than the other. Also other symptoms include: rounded shoulder, asymmetrical chest shape, a sway back…However, most people with scoliosis do not develop symptoms other than abnormal posture and cosmetic concerns, but if scoliosis is severe and untreated, it can cause additional problems: tingling or numbness in the legs, breathing problems, back pain….