• Clinical science
  • Clinician

Subdural hematoma (Subdural hemorrhage)


Subdural hematoma (SDH) refers to bleeding between the dura mater and arachnoid membrane. It is caused by head trauma that results in a tear in the bridging vein, which connects the superficial cerebral veins to the dural venous sinuses. The onset of symptoms may be acute, subacute, or chronic. Symptoms of SDH include headaches, changes in mental status, and focal neurologic deficits. CT and MRI scans are used to diagnose SDH, which presents as a crescent-shaped collection of blood that crosses the suture lines but not the falx or tentorium. Treatment may be surgical (e.g., trephination) or supportive, depending on the size of the subdural hematoma. Supportive therapy involves close clinical monitoring, normalizing coagulation parameters of patients on anticoagulant therapy, and preventing intracranial hypertension The prognosis of patients with chronic SDH is significantly better than those with acute SDH.


Classification is based on the onset of symptoms after the inciting event.

  • Acute SDH: immediately after trauma or rapidly within 72 hours
  • Subacute SDH; : 4–21 days after trauma
  • Chronic SDH: > 21 days after trauma



Sex: > (3:1)


Epidemiological data refers to the US, unless otherwise specified.


Rupture of the bridging veins caused by:

SDH may occur after trivial trauma in patients with multiple risk factors!



Clinical features

Symptoms and their onset depend on the size, location, and rate of growth of the SDH.

  • Headache
  • Impaired consciousness and confusion
  • Focal neurologic signs (i.e., hemiparesis , gait, speech, or visual impairment, personality changes, or a dilated or nonreactive pupil )
  • Memory impairment

Both SDH and epidural hematoma can occur after head trauma and cannot be differentiated based on symptoms alone!



  • SDH is diagnosed on brain imaging.
    • Non-contrast head CT scan is the modality of choice.
    • MRI is indicated when CT scan is inconclusive but suspicion for subdural hematoma is high.
  • Appearance on brain imaging
    • Crescent-shaped, concave hemorrhage that crosses suture lines but not the midline
    • Varies depending on clot age and organization:
Acute SDH Hyperdense with respect to the cortex Hypointense to isointense with respect to grey matter
Subacute SDH Isodense with respect to the cortex after 10–14 days Mostly hyperintense
Chronic SDH Hypodense with respect to the cortex and may appear isodense with respect to cerebrospinal fluid Mostly isointense with respect to cerebrospinal fluid

In contrast to SDH, epidural hematoma is lentiform on imaging and does not cross suture lines but can cross the falx or tentorium!



Treatment depends on size and onset of SDH, as well as the patient's condition.

  • General measures
  • Conservative treatment
    • Indicated if no clinical signs of herniation are present and the neurological status is stable, midline shift < 5 mm, and the hematoma is < 10 mm
    • Monitoring with serial CT scans
  • Surgical decompression


Acute management checklist


  • The prognosis of chronic SDH is better than that of acute SDH.


  • 1. Meagher RJ. Subdural Hematoma. In: Subdural Hematoma. New York, NY: WebMD. http://emedicine.medscape.com/article/1137207-overview. Updated August 4, 2016. Accessed March 1, 2017.
  • 2. Gaillard F et al. Subdural haemorrhage. https://radiopaedia.org/articles/subdural-haemorrhage. Updated February 14, 2017. Accessed February 14, 2017.
  • 3. Wagner AL. Imaging in Subdural Hematoma. In: Imaging in Subdural Hematoma. New York, NY: WebMD. http://emedicine.medscape.com/article/344482-overview#a1. Updated October 8, 2015. Accessed February 14, 2017.
  • 4. Koyfman A. Acute Subdural Hematoma in the ED. In: Acute Subdural Hematoma in the ED. New York, NY: WebMD. http://emedicine.medscape.com/article/828005-overview#a2. Updated October 27, 2016. Accessed February 14, 2017.
  • 5. Won S-Y, Dubinski D, Bruder M, Cattani A, Seifert V, Konczalla J. Acute subdural hematoma in patients on oral anticoagulant therapy: management and outcome. Neurosurg Focus. 2017; 43(5): p. E12. doi: 10.3171/2017.8.focus17421.
  • 6. Fomchenko EI, Gilmore EJ, Matouk CC, Gerrard JL, Sheth KN. Management of Subdural Hematomas: Part I. Medical Management of Subdural Hematomas. Curr Treat Options Neurol. 2018; 20(8). doi: 10.1007/s11940-018-0517-2.
  • 7. Gerard C, Busl KM. Treatment of Acute Subdural Hematoma. Curr Treat Options Neurol. 2013; 16(1). doi: 10.1007/s11940-013-0275-0.
  • 8. Engelhard HH III. Subdural Hematoma Surgery. In: Subdural Hematoma Surgery. New York, NY: WebMD. http://emedicine.medscape.com/article/247472-overview. Updated April 21, 2016. Accessed March 1, 2017.
  • 9. Wilberger JE, Dupre DA. Intracranial Hematomas. https://www.merckmanuals.com/home/injuries-and-poisoning/head-injuries/intracranial-hematomas. Updated March 1, 2017. Accessed March 1, 2017.
  • Baek H-G, Park S-H. Craniotomy and Membranectomy for Treatment of Organized Chronic Subdural Hematoma. Korean J Neurotrauma. 2018; 14(2): p. 134. doi: 10.13004/kjnt.2018.14.2.134.
  • Jr. RPG. Traumatic Brain Injury. CRC Press; 2007.
  • Lubin MF, Smith RB, Dodson TF, Spell NO, Walker HK. Medical Management of the Surgical Patient. Cambridge University Press; 2006.
  • Krishnamoorthy V, Chaikittisilpa N, Kiatchai T, Vavilala M. Hypertension After Severe Traumatic Brain Injury. J Neurosurg Anesthesiol. 2017; 29(4): pp. 382–387. doi: 10.1097/ana.0000000000000370.
  • Vella MA, Crandall ML, Patel MB. Acute Management of Traumatic Brain Injury. Surg Clin North Am. 2017; 97(5): pp. 1015–1030. doi: 10.1016/j.suc.2017.06.003.
  • Park H-R, Lee K-S, Shim J-J, Yoon S-M, Bae H-G, Doh J-W. Multiple Densities of the Chronic Subdural Hematoma in CT Scans. J Korean Neurosurg Soc. 2013; 54(1): p. 38. doi: 10.3340/jkns.2013.54.1.38.
  • Sinclair AJ, Morley JE, Vellas B. Pathy's Principles and Practice of Geriatric Medicine. John Wiley & Sons; 2012.
  • Flint AC, Chan SL, Rao VA, Efron AD, Kalani MA, Sheridan WF. Treatment of chronic subdural hematomas with subdural evacuating port system placement in the intensive care unit: evolution of practice and comparison with bur hole evacuation in the operating room. J Neurosurg. 2017; 127(6): pp. 1443–1448. doi: 10.3171/2016.9.jns161166.
  • Lewis A, Sen R, Hill TC, et al. Antibiotic prophylaxis for subdural and subgaleal drains. J Neurosurg. 2017; 126(3): pp. 908–912. doi: 10.3171/2016.4.JNS16275.
  • Small JE, Noujaim DL, Ginat DT, Kelly HR, Schaefer PW. Neuroradiology. Elsevier Health Sciences; 2018.
  • Klatt EC. Robbins and Cotran Atlas of Pathology E-Book. Elsevier Health Sciences; 2011.
  • Yadav Y, Parihar V, Namdev H, Bajaj J. Chronic subdural hematoma. Asian J Neurosurg. 2016; 11(4): p. 330. doi: 10.4103/1793-5482.145102.
  • Rybak MJ, Lomaestro BM, Rotschafer JC, et al. Vancomycin Therapeutic Guidelines: A Summary of Consensus Recommendations from the Infectious Diseases Society of America, the American Society of Health‐System Pharmacists, and the Society of Infectious Diseases Pharmacists. Clin Infect Dis. 2009; 49(3): pp. 325–327. doi: 10.1086/600877.
  • Louisdon Pierre; Noah P. Kondamudi. Subdural Hematoma. StatPearls. 2019. url: https://www.ncbi.nlm.nih.gov/books/NBK532970/.
  • Pin-on P, Saringkarinkul A, Punjasawadwong Y, Kacha S, Wilairat D. Serum electrolyte imbalance and prognostic factors of postoperative death in adult traumatic brain injury patients. Medicine. 2018; 97(45): p. e13081. doi: 10.1097/md.0000000000013081.
  • Saag MS et al. The Sanford Guide to Antimicrobial Therapy 2016. Sperryville: Antimicrobial Therapy, Inc; 2016.
  • Kim H, Suh S-J, Kang H-J, et al. Predictable Values of Decompressive Craniectomy in Patients with Acute Subdural Hematoma: Comparison between Decompressive Craniectomy after Craniotomy Group and Craniotomy Only Group. Korean J Neurotrauma. 2018; 14(1): p. 14. doi: 10.13004/kjnt.2018.14.1.14.
  • Toi H, Kinoshita K, Hirai S, et al. Present epidemiology of chronic subdural hematoma in Japan: analysis of 63,358 cases recorded in a national administrative database. J Neurosurg. 2018; 128(1): pp. 222–228. doi: 10.3171/2016.9.jns16623.
  • Holly LT, Kelly DF, Counelis GJ, Blinman T, McArthur DL, Cryer HG. Cervical spine trauma associated with moderate and severe head injury: incidence, risk factors, and injury characteristics. J Neurosurg. 2002; 96(3): pp. 285–291. doi: 10.3171/spi.2002.96.3.0285.
  • Watson RR, Zibadi S. Addictive Substances and Neurological Disease. Academic Press; 2017.
  • Wang I-K, Chen H-J, Cheng Y-K, et al. Subdural hematoma in diabetic patients. European Journal of Neurology. 2014; 22(1): pp. 99–105. doi: 10.1111/ene.12538.
  • Moran C, Beare R, Wang W, Callisaya M, Srikanth V. Type 2 diabetes mellitus, brain atrophy, and cognitive decline. Neurology. 2019; 92(8): pp. e823–e830. doi: 10.1212/wnl.0000000000006955.
  • Kemp AM. Investigating subdural haemorrhage in infants. Arch Dis Child. 2002; 86(2): pp. 98–102. doi: 10.1136/adc.86.2.98.
  • Jayawant S, Parr J. Outcome following subdural haemorrhages in infancy. Arch Dis Child. 2007; 92(4): pp. 343–347. doi: 10.1136/adc.2005.084988.
  • Aminoff MJ, Josephson SA. Aminoff's Neurology and General Medicine. Academic Press; 2014.
  • Yang AI, Balser DS, Mikheev A, et al. Cerebral atrophy is associated with development of chronic subdural haematoma. Brain injury. 2012; 26(13-14): pp. 1731–6. doi: 10.3109/02699052.2012.698364.
  • Liu X, Qiu Y, Zhang J, et al. Emergent Single Burr Hole Evacuation for Traumatic Acute Subdural Hematoma with Cerebral Herniation: A Retrospective Cohort Comparison Analysis. World Neurosurg. 2018; 120: pp. e1024–e1030. doi: 10.1016/j.wneu.2018.08.219.
  • Karibe H, Hayashi T, Hirano T, Kameyama M, Nakagawa A, Tominaga T. Surgical management of traumatic acute subdural hematoma in adults: a review. Neurol Med Chir (Tokyo). 2014; 54(11): pp. 887–94. doi: 10.2176/nmc.cr.2014-0204.
  • Kirollos R, Helmy A, Thomson S, Hutchinson P. Oxford Textbook of Neurological Surgery. Oxford University Press; 2019.
  • Adhiyaman V. Chronic subdural haematoma in the elderly. Postgrad Med J. 2002; 78(916): pp. 71–75. doi: 10.1136/pmj.78.916.71.
  • Kaufman RM, Djulbegovic B, Gernsheimer T. Platelet Transfusion: A Clinical Practice Guideline From the AABB. Ann Intern Med. 2015; 162(3): pp. 205–213. doi: 10.7326/M14-1589.
  • Frontera JA, Lewin III JJ, Rabinstein AA, et al. Guideline for Reversal of Antithrombotics in Intracranial Hemorrhage. Neurocrit Care. 2015; 24(1): pp. 6–46. doi: 10.1007/s12028-015-0222-x.
  • Seelig JM, Becker DP, Miller JD, Greenberg RP, Ward JD, Choi SC. Traumatic acute subdural hematoma: major mortality reduction in comatose patients treated within four hours. N Engl J Med. 1981; 304(25): pp. 1511–8. doi: 10.1056/NEJM198106183042503.
  • Bullock MR, Chesnut R, Ghajar J, et al. Surgical management of acute subdural hematomas. Neurosurgery. 2006; 58(3 Suppl): pp. S16–24; discussion Si–iv. pmid: 16710968.
  • Hotta K, Sorimachi T, Honda Y, Matsumae M. Chronic Subdural Hematoma in Women. World Neurosurg. 2017; 105: pp. 47–52. doi: 10.1016/j.wneu.2017.05.105.
  • Ferri FF. Ferri's Clinical Advisor 2015 E-Book. Elsevier Health Sciences; 2014.
  • Katz DI, MD DI, Zafonte RD, et al. Brain Injury Medicine. Demos Medical Publishing; 2006.
  • Dunn LT. RAISED INTRACRANIAL PRESSURE. J Neurol Neurosurg Psychiatry. 2002; 73(suppl 1): pp. i23–i27. doi: 10.1136/jnnp.73.suppl_1.i23.
  • ENA. Sheehy’s Manual of Emergency Care - E-Book. Elsevier Health Sciences; 2012.
  • Kahan S, Raves JJ. In a Page: Surgery. Lippincott Williams & Wilkins; 2004.
  • Larner AJ, Coles AJ, Scolding NJ, Barker RA. A-Z of Neurological Practice. Springer Science & Business Media; 2011.
  • Power A, Hamady M, Singh S, Ashby D, Taube D, Duncan N. High but stable incidence of subdural haematoma in haemodialysis--a single-centre study. Nephrol Dial Transplant. 2010; 25(7): pp. 2272–2275. doi: 10.1093/ndt/gfq013.
  • Kwon YS, Yang KH, Lee YH. Craniotomy or Decompressive Craniectomy for Acute Subdural Hematomas: Surgical Selection and Clinical Outcome. Korean J Neurotrauma. 2016; 12(1): p. 22. doi: 10.13004/kjnt.2016.12.1.22.
  • Fomchenko EI, Gilmore EJ, Matouk CC, Gerrard JL, Sheth KN. Management of Subdural Hematomas: Part II. Surgical Management of Subdural Hematomas. Curr Treat Options Neurol. 2018; 20(8). doi: 10.1007/s11940-018-0518-1.
  • Murphy JG, Lloyd MA. Mayo Clinic Cardiology Concise Textbook and Mayo Clinic Cardiology Board Review Questions & Answers. CRC Press; 2007.
  • Zasler N, Katz D, MD D, Zafonte R, DO R. Brain Injury Medicine. Demos Medical Publishing; 2007.
  • Grelat M, Madkouri R, Bousquet O. Acute isodense subdural hematoma on computed tomography scan – diagnostic and therapeutic trap: a case report. J Med Case Reports. 2016; 10(1). doi: 10.1186/s13256-016-0822-x.
  • Castillo M. Neuroradiology. Lippincott Williams & Wilkins; 2002.
  • Lee S-H, Choi J-I, Lim D-J, Ha S-K, Kim S-D, Kim S-H. The Potential of Diffusion-Weighted Magnetic Resonance Imaging for Predicting the Outcomes of Chronic Subdural Hematomas. Journal of Korean Neurosurgical Society. 2018; 61(1): pp. 97–104. doi: 10.3340/jkns.2016.0606.005.
  • Bullock MR, Chesnut R, Ghajar J, et al. Guidelines for the Surgical Management of Traumatic Brain Injury Author Group. Neurosurgery. 2006; 58(3): pp. S2–vi–S2–vi. doi: 10.1093/neurosurgery/58.3.vi.
  • Dougherty DD, Rauch SL, Rosenbaum JF. Essentials of Neuroimaging for Clinical Practice. American Psychiatric Pub; 2008.
  • Ogunlade J, Wiginton JG, Ghanchi H, et al. Efficacy of platelet transfusion in the management of acute subdural hematoma. Clin Neurol Neurosurg. 2018; 174: pp. 163–166. doi: 10.1016/j.clineuro.2018.09.021.
  • Stolla M, Zhang F, Meyer MR, Zhang J, Dong J. Current state of transfusion in traumatic brain injury and associated coagulopathy. Transfusion (Paris). 2019; 59(S2): pp. 1522–1528. doi: 10.1111/trf.15169.
  • Sarov M, Guichard J-P, Chibarro S, et al. Sinking Skin Flap Syndrome and Paradoxical Herniation After Hemicraniectomy for Malignant Hemispheric Infarction. Stroke. 2010; 41(3): pp. 560–562. doi: 10.1161/strokeaha.109.568543.
  • Ashayeri K, Jackson EM, Huang J, Brem H, Gordon CR. Syndrome of the Trephined. Neurosurgery. 2016; 79(4): pp. 525–534. doi: 10.1227/neu.0000000000001366.
  • Zhang J, Jin D, Pan K-H. Epidural blood patch for spontaneous intracranial hypotension with chronic subdural haematoma: A case report and literature review. J Int Med Res. 2016; 44(4): pp. 976–981. doi: 10.1177/0300060516645955.
last updated 10/16/2020
{{uncollapseSections(['y6adnl', 'ZpaZLl', 'xkcEJc0', '-6aDnl', 'CkcqJc0', 'apaQLl', 'Xpa9Ll', 'WpaPol', 'LIXwWz', 'B4czlc0'])}}