For those who experienced improved breathing after spinal fusion, the results are typically linked to having had severe, restrictive scoliosis. The surgery straightens the torso, which can create more space for the lungs to expand. The extent of improvement is often described as moderate but life-changing—patients report being less short of breath during routine activities, having a greater lung capacity, and suffering from fewer respiratory infections. While the primary reason for surgery is usually severe pain or progressive deformity, the significant secondary gain of improved respiratory function often makes the arduous recovery and risks of the major surgery feel worthwhile, substantially enhancing their overall quality of life.