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Hip and groin red flags

What you cannot afford to miss in hip and groin pain, before any special test.

Most hip and groin pain is musculoskeletal. These are the conditions that are not, or that need referral before treatment, with the features that point to each. Every row carries its source, listed at the foot of the page.

Use with your local protocols. Referral pathways, and how urgently to act, differ between health services and countries: where your local protocol or current guideline differs, follow it. Never delay emergency care to check a protocol.

Can’t missWhat points to it
Bone stress injury of the femoral neck1,2A runner, recruit or endurance athlete with groin pain that increases with loading and does not settle, particularly with a recent increase in training or low energy availability. The patient should stop weight-bearing (using crutches), and same-day medical assessment and imaging should be arranged. A normal X-ray does not exclude the diagnosis; MRI is the second-line test.
Hip fracture in an older adult3,4A fall followed by groin or hip pain, inability to weight-bear, or a shortened, externally rotated leg. Some patients with an impacted fracture can still walk, and the initial X-ray can appear normal. Same-day emergency referral is required, as delay to surgery is associated with higher mortality.
Septic arthritis5,6An acutely painful hip with restriction of all movements and refusal to weight-bear, with or without fever or malaise. Fever is often absent in confirmed cases, so a normal temperature does not exclude infection. Same-day medical assessment is required. The risk is higher in patients with a prosthesis, immunosuppression or a recent injection.
Deep vein thrombosis7Unilateral thigh or calf swelling, warmth and tenderness, particularly after hip surgery, immobilisation or travel. This requires same-day medical assessment and should not be managed as a muscle strain.
Slipped capital femoral epiphysis8An adolescent, often an overweight boy, with a limp, pain in the hip, thigh or knee, and painful or restricted internal rotation. Presentation with knee pain alone is a well-recognised pitfall. The patient should stop weight-bearing (using crutches), and same-day medical assessment should be arranged for X-rays and orthopaedic referral.
Perthes disease9A younger child, usually a primary-school-aged boy, with an intermittent limp and mild hip, thigh or knee pain. The child should be referred for radiographs rather than managed as having a strain.
Metastasis or primary bone tumour10,11The proximal femur and pelvis are common sites of metastasis. A history of cancer, constant or night pain not relieved by rest or change of position, or unexplained weight loss requires urgent (not same-day) medical review and imaging.
Avascular necrosis12Progressive groin pain without injury in a patient with long-term corticosteroid use, heavy alcohol use or sickle cell disease. Examination can be unremarkable in the early stages. Prompt (not same-day) referral for MRI is indicated while the joint can still be preserved.
Abdominal, vascular, urological or hernia causes13,14,15Sudden severe testicular pain or swelling, or an irreducible tender groin lump in an unwell patient, is a surgical emergency. A reducible lump or cough impulse suggests a hernia: refer for a surgical opinion. A pulsatile abdominal mass in a patient with back, abdominal or groin pain, or who is unwell, may be a leaking aortic aneurysm: call an ambulance. A pulsatile mass found in the absence of pain requires urgent medical assessment (see low back red flags).
Pelvic apophyseal avulsion16An adolescent athlete with sudden pain while sprinting or kicking, and point tenderness over the anterior superior or anterior inferior iliac spine or the ischial tuberosity. This is often an avulsion fracture rather than a strain, and imaging changes management.
Lumbar spine masquerading as hip17Back pain accompanying the leg pain, symptoms in a band extending below the knee, dermatomal numbness or reflex change, and a full, painless range of hip movement point to the spine. See low back red flags.

A red flag raises suspicion; it does not make the diagnosis, and its absence does not rule the condition out. The table is not a complete list of every serious condition, and it is not a clinical protocol. When a red flag is present, act on the referral advice in the row, in line with your local protocols. This page is for registered health practitioners and students and is not clinical advice for patients; see the terms of use.

Last checked against the cited sources: 15 October 2026.

Then the tests: Hip and groin special tests, with sensitivity, specificity and likelihood ratios.

Get the book for telling the hip joint from the lateral hip, and ruling out the runner's stress fracture first

This table opens the chapter ‘The hip and groin’ in Rule It In, Rule It Out. The book then works through the questions that matter in this region, with the published figures for each test and how to read them.

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Sources

  1. Robertson GAJ, Wood AM. Femoral Neck Stress Fractures in Sport: A Current Concepts Review. Sports Med Int Open. 2017;1(2):E58–E68. Link
  2. Mountjoy M, Sundgot-Borgen JK, Burke LM, et al. IOC consensus statement on relative energy deficiency in sport (RED-S): 2018 update. Br J Sports Med. 2018;52(11):687–697. Link
  3. Schroeder JD, Turner SP, Buck E. Hip Fractures: Diagnosis and Management. Am Fam Physician. 2022;106(6):675–683. Link
  4. Hossain M, Barwick C, Sinha AK, Andrew JG. Is magnetic resonance imaging (MRI) necessary to exclude occult hip fracture? Injury. 2007;38(10):1204–1208. Link
  5. Margaretten ME, Kohlwes J, Moore D, Bent S. Does this adult patient have septic arthritis? JAMA. 2007;297(13):1478–1488. Link
  6. Mathews CJ, Weston VC, Jones A, Field M, Coakley G. Bacterial septic arthritis in adults. Lancet. 2010;375(9717):846–855. Link
  7. Wells PS, Anderson DR, Rodger M, et al. Evaluation of D-dimer in the diagnosis of suspected deep-vein thrombosis. N Engl J Med. 2003;349(13):1227–1235. Link
  8. Webb CW, Liu R, Bouchereau-Lal N. Slipped Capital Femoral Epiphysis: Rapid Evidence Review. Am Fam Physician. 2025;112(4):414–423. Link
  9. Sabry AO, Li D. Legg-Calvé-Perthes Disease. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; updated March 25, 2026. Link
  10. Coleman RE. Clinical features of metastatic bone disease and risk of skeletal morbidity. Clin Cancer Res. 2006;12(20):6243s–6249s. Link
  11. National Institute for Health and Care Excellence. Suspected cancer: recognition and referral. NICE guideline NG12. 2015 (last updated 2023). Link
  12. Matthews AH, Davis DD, Fish MJ, Stitson D. Avascular Necrosis. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; updated August 28, 2023. Link
  13. HerniaSurge Group. International guidelines for groin hernia management. Hernia. 2018;22(1):1–165. Link
  14. Sharp VJ, Kieran K, Arlen AM. Testicular torsion: diagnosis, evaluation, and management. Am Fam Physician. 2013;88(12):835–840. Link
  15. Chaikof EL, Dalman RL, Eskandari MK, et al. The Society for Vascular Surgery practice guidelines on the care of patients with an abdominal aortic aneurysm. J Vasc Surg. 2018;67(1):2–77.e2. Link
  16. Schuett DJ, Bomar JD, Pennock AT. Pelvic Apophyseal Avulsion Fractures: A Retrospective Review of 228 Cases. J Pediatr Orthop. 2015;35(6):617–623. Link
  17. Brown MD, Gomez-Marin O, Brookfield KF, Li PS. Differential diagnosis of hip disease versus spine disease. Clin Orthop Relat Res. 2004;(419):280–284. Link

Red flags for other regions: Neck · Shoulder · Elbow · Wrist and hand · Thoracic spine and chest wall · Low back and pelvis · Knee · Ankle and foot

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