Ankylosing spondylitis (AS) is a type of chronic (long-term) arthritis that affects parts of the spine, including bones, muscles and ligaments.
Our Health A-Z contains more information on Ankylosing spondylitis.
Coccydynia is a type of lower back pain felt around the last bone at the base of the spine (known as the coccyx or tailbone).
Our Health A-Z contains more information on Pain at base of spine.
Important: If you have these symptoms, they may be unrelated to any of these conditions listed. If you are concerned about your symptoms then you should see a doctor.