“It’s just my back from the gym”

Chronic low back pain in a young adult that is WORSE with rest and BETTER with exercise, with night pain and prolonged morning stiffness, onset <40 and alternating buttock pain, is INFLAMMATORY back pain (suggesting axial spondyloarthritis), not a mechanical/gym injury — and must not be accepted as such. The action is rheumatology referral under NICE NG65 (he meets 4 or more criteria), with inflammatory markers and HLA-B27 sent alongside if helpful — neither rules it out — and diagnostic imaging (MRI of the sacroiliac joints and spine) left to rheumatology (NICE NG65; NICE QS170), plus first-line NSAIDs and a structured exercise/physiotherapy programme (which genuinely help). Extra-articular clues — a past painful red eye (uveitis), psoriasis, IBD, family history — support the diagnosis. Crucially, even when the story is inflammatory, the CAUDA EQUINA red-flag screen must be performed and documented (saddle anaesthesia, bladder/bowel or sexual dysfunction, bilateral/progressive leg neurology → emergency MRI/A&E; GIRFT 2023). The hidden agenda is fear masked by "I just push through": dread of disability (an uncle with ankylosing spondylitis), impact on mood/relationship, and worry about a physically demanding job. Surface it, give realistic hope (early diagnosis transforms outcomes; effective treatments exist), and safety-net the cauda equina emergency clearly.