Lordosis is the inward curve of the lumbar spine (just above the buttocks). A small degree of lordosis is normal. Too much curving is called swayback.| medlineplus.gov
Kyphosis is a curving of the spine that causes a bowing or rounding of the back. This leads to a hunchback or slouching posture.| medlineplus.gov
Spinal stenosis is narrowing of the spinal column that causes pressure on the spinal cord, or narrowing of the openings (called neural foramina) where spinal nerves leave the spinal column.| medlineplus.gov