Low back pain affects up to 95% of people as non‑specific mechanical pain, but a small proportion hides serious pathology such as cancer, infection, fracture or cauda equina syndrome. The first clinical step is diagnostic triage – sorting every patient into non‑specific, radicular or red‑flag groups – because this decision drives imaging, treatment and urgency. Missing cauda equina can lead to permanent bladder, bowel and sexual dysfunction, so asking about saddle anaesthesia and bladder function is essential in every significant back‑or‑leg‑pain presentation. ⏱ Chapters 0:00 Intro 1:26 The Three-Way Fork 2:20 Many Pain Sources — Imaging Cannot Localise… 3:01 The Emergency You Cannot Miss 3:56 Red Flags — Tuna Fish 4:53 The Scan That Lies 5:49 When To Image 6:42 The Leg Tells You The Level 7:38 Traversing Root Vs Exiting Root 8:19 What Actually Helps 9:12 Yellow Flags Predict Chronicity, Not Disease 10:32 Recap & sources This video explains the diagnostic triage for low back pain, detailing how to distinguish the overwhelming majority of non‑specific mechanical pain from radicular pain and the small but critical fraction of serious specific pathology flagged by red flags. It covers the red‑flag mnemonics (TUNA FISH), the cauda equina emergency (SBBL), why routine imaging is discouraged, and the evidence‑based non‑operative management pathway that focuses on staying active, appropriate analgesia and addressing yellow flags. Understanding this framework prevents missed emergencies, avoids unnecessary investigations and guides effective, patient‑centred care. 🦴 IN THIS VIDEO YOU'LL LEARN • How to perform the three‑way triage of low back pain into non‑specific, radicular and serious pathology groups • Recognise the red‑flag features of malignancy, infection, fracture and inflammatory disease using the TUNA FISH mnemonic • Identify cauda equina syndrome by saddle anaesthesia, bladder dysfunction, bowel incontinence and bilateral leg signs (SBBL) • Understand why routine lumbar imaging is of low specificity and can worsen outcomes in non‑specific low back pain • Apply the ACTIVE management mnemonic to guide advice, exercise, analgesia and psychosocial assessment • Differentiate neurogenic urinary retention (CES‑R) from incomplete cauda equina (CES‑I) and their prognostic implications • Know when urgent MRI and emergency surgical decompression are indicated for suspected cauda equina • Use yellow‑flag screening tools such as STarT Back to target interventions that prevent chronic disability 📌 KEY TAKEAWAYS ✔️ Triage first: non‑specific vs radicular vs red‑flag directs every subsequent decision ✔️ Cauda equina is a surgical emergency – saddle anaesthesia plus bladder/bowel/sexual dysfunction demands urgent MRI and decompression ✔️ Routine imaging for ordinary low back pain is harmful; reserve scans for red flags, progressive neurology or surgical radicular pain ✔️ Stay active, use NSAIDs as first‑line analgesia and address yellow flags to prevent chronicity ✔️ Remember TUNA FISH for red flags and SBBL for cauda equina – they save lives and function ✔️ Effective management combines reassurance, exercise, biopsychosocial care and avoidance of routine opioids 👩⚕️ WHO THIS IS FOR This lecture is designed for orthopaedic trainees, medical students, junior doctors and allied health professionals who encounter low back pain in clinical practice. It is also valuable for interested patients seeking a clear, evidence‑based understanding of when back pain warrants further investigation. 📚 RELATED TOPICS: Radiculopathy and sciatica assessment · Spinal metastasis red flags · Vertebral osteoporotic fracture evaluation · Inflammatory back pain and axial spondyloarthritis · Psychosocial yellow flags and STarT Back tool · Lumbar disc herniation indications for surgery 🔗 More free orthopaedic teaching at Orthovellum.com — subscribe for weekly videos. 🎨 CREDITS • Original Orthovellum production. ⚠️ DISCLAIMER: Educational only — not individual medical advice. Always consult a qualified clinician for diagnosis and treatment. #lowbackpain #redflags #caudaequina #triage #nonspecificpain #radiculopathy #spinehealth #backpainmanagement #orthopaedics #physiotherapy #yellowflags #imagingguidelines