• A decrease in pulmonary function and lung disease may occur when a curve affects the ribs. This occurs only in severe thoracic curves.
• Back pain, disabling lung disease and increased stress on the heart may occur in adults.
• Pressure on the nerves may cause neurological problems.
• Arthritis and disc disease may result from severe lumbar curves.

22. X-ray of an untreated scoliosis patient with an 85 degrees congenital thoracic curve
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Courtesy of Stuart Weinstein, MD, UIHC Department of Orthopaedics

Pregnancy does not usually increase curvature or the occurrence of the above problems.