Doctors use X-ray images of a person's spine to measure spinal curvature. A curve or angle of the spine is measured in degrees and describes how severe the curve is. (The angle is determined by the intersection of lines projected from the top and bottom of the curve.) If the spine is straight, there is no angle; this would be a 0-degree curve. If the spine is curved, the angle can be measured. The larger the curve, the larger the angle or degree measurement. For example, a 10-degree curve is considered a mild curve, and a 50-degree curve is considered a severe curve.
Many people have some curve in their spine. In fact, spinal curves that are less than 10 degrees are considered a normal variation of the spine. Curves that are greater than 10 degrees may be monitored (to see whether the curve is getting worse) or may need treatment.
In addition to the severity of the curve, curves are described by their direction and location.
Direction is based on which way the curve bends away from the center of the body. For example, if the inner side of the curve is to the right, it is called a right curve.
Location is determined by the spinal bone at the center of the curve. The spine is divided into three parts: neck region (cervical), chest area (thoracic), and lower back (lumbar). A curve may be labeled according to the number of spinal bones involved. For example, T5 to T12 means that the curve involves the 5th through the 12th chest (thoracic) spinal bones.