[Durgical](https://durgical.com/en/) › [DurgiPedia](https://durgical.com/en/durgipedia/) › [Conditions](https://durgical.com/en/conditions/) › Hypovolaemic shock [Conditions](https://durgical.com/en/conditions/) · [Systemic conditions](https://durgical.com/en/conditions/) # Hypovolaemic shock Hypovolaemic shock is a life-threatening state in which the body loses so much blood or fluid that organs no longer get enough blood flow. Updated 2026-10-29 ## Structures involved Tap one to see what it is and open it in 3D. - [Left ventricle](https://durgical.com/en/anatomy/left-ventricle/) - [Inferior vena cava](https://durgical.com/en/anatomy/inferior-vena-cava/) - [Kidneys](https://durgical.com/en/anatomy/kidney/) - [Abdominal aorta](https://durgical.com/en/anatomy/abdominal-aorta/) - [Spleen](https://durgical.com/en/anatomy/spleen/) - [Liver](https://durgical.com/en/anatomy/liver/) - [Superior vena cava](https://durgical.com/en/anatomy/superior-vena-cava/) - [Pleura](https://durgical.com/en/anatomy/pleura/) ## In biochemistry - [Lactate](https://durgical.com/en/biochemistry/molecules/lactate/) ## In the clinical exam - [Shock: the clinical signs and the types](https://durgical.com/en/clinical-exam/shock-the-clinical-signs-and-the-types/) - [Hydration status: signs of dehydration](https://durgical.com/en/clinical-exam/hydration-status-signs-of-dehydration/) - [Capillary refill time](https://durgical.com/en/clinical-exam/capillary-refill-time/) - [Dehydration and fluid overload](https://durgical.com/en/clinical-exam/dehydration-and-fluid-overload/) ## In physiology - [The Frank–Starling mechanism](https://durgical.com/en/physiology/the-frank-starling-mechanism/) - [Cardiac output and what sets it](https://durgical.com/en/physiology/cardiac-output-and-what-sets-it/) - [The baroreceptor reflex](https://durgical.com/en/physiology/the-baroreceptor-reflex/) - [Shock physiology](https://durgical.com/en/physiology/shock-physiology/) - [Venous return and the Guyton curves](https://durgical.com/en/physiology/venous-return-and-the-guyton-curves/) - [Central venous pressure and the jugular pulse](https://durgical.com/en/physiology/central-venous-pressure-and-the-jugular-pulse/) - [Nervous control of the circulation and the CNS ischemic response](https://durgical.com/en/physiology/nervous-control-of-the-circulation-and-the-cns-ischemic-response/) - [The response to standing up](https://durgical.com/en/physiology/the-response-to-standing-up/) - [Skin blood flow](https://durgical.com/en/physiology/skin-blood-flow/) - [Body fluid compartments](https://durgical.com/en/physiology/body-fluid-compartments/) - [The endocrine stress response](https://durgical.com/en/physiology/the-endocrine-stress-response/) - [Water and electrolyte absorption and how diarrhea happens](https://durgical.com/en/physiology/water-and-electrolyte-absorption-and-how-diarrhea-happens/) - [Splanchnic and portal circulation](https://durgical.com/en/physiology/splanchnic-and-portal-circulation/) - [Physiology of the vital signs (including blood pressure measurement)](https://durgical.com/en/physiology/physiology-of-the-vital-signs/) - [Glomerular filtration: the barrier and its determinants](https://durgical.com/en/physiology/glomerular-filtration-the-barrier-and-its-determinants/) - [Sodium and extracellular volume regulation (with natriuretic peptides)](https://durgical.com/en/physiology/sodium-and-extracellular-volume-regulation/) - [Renal blood flow, autoregulation and tubuloglomerular feedback](https://durgical.com/en/physiology/renal-blood-flow-autoregulation-and-tubuloglomerular-feedback/) - [Fluid shifts between compartments](https://durgical.com/en/physiology/fluid-shifts-between-compartments/) - [Dehydration and fluid overload](https://durgical.com/en/physiology/dehydration-and-fluid-overload/) - [IV fluids: tonicity and where they go](https://durgical.com/en/physiology/iv-fluids-tonicity-and-where-they-go/) - [Oxygen content, delivery and extraction](https://durgical.com/en/physiology/oxygen-content-delivery-and-extraction/) ## Why it happens - [Shock: types, stages and the organs it damages](https://durgical.com/en/general-pathology/shock-types-stages-and-the-organs-it-damages/) - [Watershed areas and the organs most sensitive to ischemia](https://durgical.com/en/general-pathology/watershed-areas-and-the-organs-most-sensitive-to-ischemia/) - [Thermal injury: burns, hyperthermia and hypothermia](https://durgical.com/en/general-pathology/thermal-injury-burns-hyperthermia-and-hypothermia/) - [Hemorrhage: petechiae, purpura, ecchymosis, hematoma, and what blood loss does](https://durgical.com/en/general-pathology/hemorrhage-petechiae-purpura-ecchymosis-hematoma-and-what-blood-loss-does/) ## What it is A life-threatening state of poor tissue perfusion caused by loss of intravascular volume, from bleeding (haemorrhagic shock) or from fluid losses such as vomiting, diarrhoea, burns or diuresis. ## Who gets it Haemorrhage is a leading preventable cause of death after trauma, which in Colombia includes road traffic injuries and violence. Diarrhoeal dehydration remains an important cause of hypovolaemia in young children. ## Causes - Haemorrhage: trauma (chest, abdomen, pelvis, long bones, external), gastrointestinal bleeding, ruptured aortic aneurysm, ectopic pregnancy, postpartum haemorrhage - Gastrointestinal losses: vomiting and diarrhoea - Kidney losses: osmotic diuresis (diabetic ketoacidosis), diuretics, adrenal insufficiency - [Skin](https://durgical.com/en/anatomy/skin/) losses: burns, heat illness - Third-space losses: pancreatitis, bowel obstruction, sepsis capillary leak ## Risk factors - Major trauma - Anticoagulant or antiplatelet use - Extremes of age - Severe gastroenteritis in infants - Limited access to early care ## Pathophysiology Reduced venous return lowers preload, stroke volume and cardiac output. Sympathetic activation causes tachycardia and vasoconstriction, keeping blood pressure normal at first. As losses grow, compensation fails: hypotension, anaerobic metabolism and lactic acidosis follow. In trauma, hypothermia, acidosis and coagulopathy reinforce each other (the lethal triad). ## Classification - Haemorrhagic shock classes (ATLS) by estimated blood loss: class I (up to about 15%), II (15 to 30%), III (30 to 40%) and IV (over 40%) - Non-haemorrhagic hypovolaemia (fluid losses) - Compensated or decompensated shock ## Symptoms and signs - Early: tachycardia, anxiety, cool pale skin, delayed capillary refill, narrowed pulse pressure - Thirst, dry mucous membranes (dehydration) - Reduced urine output - Late: hypotension, confusion or drowsiness, rapid breathing - Visible bleeding or signs of internal bleeding (distended abdomen, pelvic or femoral deformity) ## Red flags - Hypotension, which is a late sign: a large volume has already been lost - Altered mental status - Urine output near zero - Rising lactate or base deficit - Ongoing bleeding despite fluids (needs surgical or procedural control) - Children and older adults or those on beta blockers may not show tachycardia ## Diagnosis **Clinical** A clinical diagnosis: a source of loss plus signs of hypoperfusion. In trauma the primary survey (ABCDE) looks for bleeding in the [chest](https://durgical.com/en/anatomy/region/chest/), [abdomen](https://durgical.com/en/anatomy/region/abdomen/), [pelvis](https://durgical.com/en/anatomy/region/pelvis/), long bones and externally; the shock index (heart rate divided by systolic pressure) helps. **Tests** Lactate and base deficit (perfusion), haemoglobin (may be normal early in acute bleeding), blood type and cross-match, coagulation tests or viscoelastic testing, electrolytes, [kidney](https://durgical.com/en/anatomy/kidney/) function and blood gas. **Imaging** Bedside ultrasound (FAST/eFAST) for blood in the abdomen, [pericardium](https://durgical.com/en/anatomy/pericardium/) or chest; chest and pelvic X-rays in trauma; CT once the patient is stable; ultrasound of the [inferior vena cava](https://durgical.com/en/anatomy/inferior-vena-cava/) to estimate volume status. ## Differential diagnosis - Cardiogenic shock (myocardial infarction) - Obstructive shock (tension pneumothorax, cardiac tamponade, pulmonary embolism) - Septic shock - Anaphylactic shock - Neurogenic shock ([spinal cord](https://durgical.com/en/anatomy/spinal-cord/) injury) ## Goal of treatment Stop the loss, restore circulating volume and oxygen delivery quickly, and prevent organ failure and the lethal triad of hypothermia, acidosis and coagulopathy. ## Treatment **Acute** Haemorrhage control first: direct pressure, tourniquets, pelvic binder; urgent surgery or interventional radiology for internal bleeding. **Acute** Haemorrhagic shock: early balanced blood products (massive transfusion protocol), little crystalloid, permissive hypotension until bleeding is controlled (not in head injury), early antifibrinolytic in trauma. **Acute** Non-haemorrhagic losses: warmed isotonic crystalloids given in boluses with reassessment, and correction of electrolytes. **Follow-up** Heart rate, blood pressure, urine output, mental status, lactate and temperature to guide resuscitation. **Medical** Treating the cause: for example antiemetics, insulin and fluids in ketoacidosis, or hormone replacement in adrenal crisis. ## Drugs for this condition - [Ketamine](https://durgical.com/en/pharmacology/ketamine/) - [Human albumin](https://durgical.com/en/pharmacology/human-albumin/) - [Sodium hydrogen carbonate](https://durgical.com/en/pharmacology/sodium-hydrogen-carbonate/) ## Complications - Acute kidney injury - Multiple organ dysfunction - Coagulopathy and dilution from large volumes of crystalloid - Hypothermia and metabolic acidosis - Abdominal compartment syndrome - Cardiac arrest and death ## Prognosis Depends on the cause, the amount lost and how quickly the source is controlled. Early haemorrhage control and blood product resuscitation improve survival; prolonged shock leads to irreversible organ failure. ## Prevention - Road safety and injury prevention - Oral rehydration for diarrhoea in children - Early recognition and treatment of bleeding in hospital and before arrival ## Test yourself Think of the answer, then tap the question to see it. ## Which is an early sign of hypovolaemic shock, and which is late? Tachycardia (with cool skin and narrowed pulse pressure) is early; hypotension is late, as compensation has failed after a large loss. ## From which ATLS class of haemorrhagic shock does systolic blood pressure usually fall? Class III (about 30 to 40% of blood volume lost); classes I and II usually keep a normal blood pressure. ## What is the lethal triad of trauma? Hypothermia, acidosis and coagulopathy, which worsen each other and increase bleeding and death. ## Why is large-volume crystalloid avoided in haemorrhagic shock? It dilutes clotting factors and red cells, cools the patient and can worsen bleeding; early balanced blood products are preferred. ## Why may haemoglobin be normal right after acute bleeding? Whole blood is lost in proportion, so the concentration falls only after fluid shifts in or is given; normal haemoglobin does not exclude major blood loss. [Add to my cards (5)](https://durgical.app/estudiar/?add=/en/conditions/hypovolaemic-shock/) ## Related conditions - [Popliteal Artery Injury](https://durgical.com/en/conditions/popliteal-artery-injury/) - [Postpartum haemorrhage](https://durgical.com/en/conditions/postpartum-haemorrhage/) - [Placental abruption](https://durgical.com/en/conditions/placental-abruption/) - [Ectopic pregnancy](https://durgical.com/en/conditions/ectopic-pregnancy/) - [Acute (viral) gastroenteritis](https://durgical.com/en/conditions/acute-gastroenteritis/) - [Splenic injury](https://durgical.com/en/conditions/splenic-injury/) - [Acute kidney injury](https://durgical.com/en/conditions/acute-kidney-injury/) - [Femoral shaft fracture](https://durgical.com/en/conditions/femoral-shaft-fracture/) Educational information, not medical advice. For any symptom, see a health professional. Sources: [Hypovolemia and Hypovolemic Shock](https://www.ncbi.nlm.nih.gov/books/NBK513297/) (StatPearls (NCBI Bookshelf), 2025). 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