Ankylosing spondylitis pain in the sacral and tailbone region

Sacroiliac pain is often deep in one or both buttocks and may alternate sides. The sacrococcygeal region lies lower, where the sacrum meets the coccyx, and is more likely to hurt directly with sitting or pressure. Location alone cannot identify the cause, so the pattern and examination matter.

Inflammation of the sacroiliac joints is a defining feature clinicians assess in ankylosing spondylitis. The condition often presents with buttock or low-back stiffness after rest, night discomfort, and improvement after getting moving. Pain centred over the coccyx may instead follow a fall, prolonged pressure, pelvic-floor tension, or irritation of nearby tissues.

A clinician may press on specific landmarks, assess hip and spinal movement, check the nerves in the legs, and decide whether sacroiliac imaging is useful. Imaging findings must be interpreted alongside symptoms because pain can also arise from muscles, discs, hips, or nerves.

Change position regularly and break up long periods of sitting. If pressure on the coccyx triggers pain, a supportive seat cushion with a rear cut-out may reduce direct loading. Gentle walking and prescribed mobility exercises can help inflammatory stiffness, while painful heavy lifting or impact may need temporary modification.

Book a review if the pain is new, follows trauma, persists, or behaves differently from your established ankylosing spondylitis symptoms. Describe the exact tender point, night symptoms, morning stiffness, bowel or bladder changes, and any pain or tingling into a leg. Treatment may include physiotherapy and adjustment of anti-inflammatory treatment when clinically suitable.

Seek emergency care for new numbness around the genitals or inner thighs, difficulty starting or controlling urination, loss of bowel control, or new weakness in both legs. These symptoms can indicate serious pressure on the spinal nerves.

Urgent assessment is also appropriate after a major fall or impact, or when severe pain occurs with fever, feeling acutely unwell, unexplained swelling, or an inability to bear weight. Do not wait for a routine ankylosing spondylitis appointment when these features are present.

Ask whether the examination suggests sacroiliac inflammation, coccyx irritation, hip involvement, or nerve pain. Clarify whether imaging would change management, which sitting modifications fit the suspected source, and how to progress exercise without repeatedly aggravating the area.