What ankylosing spondylitis can involve
Ankylosing spondylitis is a form of inflammatory arthritis that mostly affects the spine and the joints at the base of it. The stiffness is worst after rest, which is why mornings and long meetings are the hard part, and why it eases once you keep moving. That is close to the opposite of ordinary back pain, and it is often why a diagnosis takes years.
Fatigue is part of it, and so is eye inflammation, which needs seeing about quickly. Because rheumatology appointments are far apart, how long the morning stiffness lasts is one of the most useful things to have written down. It is a number you can say out loud, rather than trying to describe a feeling.