Why does ankylosing spondylitis cause morning joint stiffness?

Ankylosing spondylitis can inflame the joints and attachment points around the spine and pelvis. During sleep, these areas remain in a similar position for a prolonged rest period, and the muscles may become protective and tight. On waking, the first movements stretch tissues that have been irritated, creating stiffness in the back, hips, or other joints. The pattern can vary, and stiffness that eases with gentle movement is useful information for your clinician.

Try gentle range-of-motion movements before getting out of bed, such as slow ankle, knee, or hip movements if they are comfortable. A warm shower or heat applied safely may help relax tight muscles. Build a consistent routine of mobility, posture, and strengthening exercises prescribed by a physiotherapist. Avoid forcing a painful stretch; gradual movement and pacing are usually more useful than a sudden strenuous session.

Tell your clinician if morning stiffness lasts longer than usual, is becoming more limiting, or is accompanied by new weakness, numbness, fever, or significant night pain. Sudden severe spinal pain after a fall or other injury requires urgent assessment.

Ask how long your morning routine should take, which movements suit your affected joints, how to recognise a flare, and whether your current treatment needs adjustment.