The conditions and the treatments
Ankylosing spondylitis and non‑radiographic axial spondyloarthritis are types of inflammatory arthritis. They are long‑term, progressive conditions. In ankylosing spondylitis, changes on X‑ray can be seen to the spine and/or the sacroiliac joints (the sacroiliac joints are located at the lower end of the spine, connecting it to the hip bones). In non‑radiographic axial spondyloarthritis, changes on the X‑ray cannot be seen but there are symptoms. The main symptom is back pain.
Treatment includes non‑steroidal anti‑inflammatory drugs (NSAIDS) that reduce inflammation as well as pain. These may not work, or be unsuitable because they cause problems with your stomach or other medical conditions.
In people with inflammatory arthritis, a protein called tumour necrosis factor (TNF) is over‑produced in the body. This causes inflammation and damage to bones, cartilage and tissue. TNF‑alpha inhibitors block the action of TNF and can reduce inflammation.
NHS Choices may be a good place to find out more.