Go through these in order and stop at the first one that applies. If you are reading this for someone else, answer for them.
Neurologic symptoms, serious breathing problems, or severe pain after an injury require emergency care.
Do not stop a prescribed medicine without guidance unless urgent medical instructions say otherwise.
A painful red eye with light sensitivity needs same-day assessment.
Regular follow-up helps the care team assess pain, stiffness, mobility, fatigue, daily function, and treatment side effects.
The schedule depends on disease activity and the medicines being used.
Routine visits may include examination of the spine and joints, blood tests, review of exercise goals, and discussion of eye, skin, or bowel symptoms.
Repeated spinal X-rays are not needed at every visit but may be used when the result could change management.
Between routine appointments, arrange earlier review if symptoms are steadily worsening, treatment is no longer helping, or medicine side effects develop.
The article also says
People taking medicines that affect the immune system should discuss infection precautions and vaccination with their care team.
Contact the prescribing clinician about fever, a significant infection, or plans for surgery.
Pregnancy planning should be discussed in advance because some medicines may need review before conception, during pregnancy, or while breastfeeding.
Every sign above is quoted from the sofidex article on Ankylosing spondylitis. If you are not sure, err upward — it is always reasonable to be checked.