Bedside Snapshot
- Normal (Adult)
- 3.5–5.0 g/dL (35–50 g/L)
- Critical Values
- No universal critical value: interpret by trend and clinical context
- High Suggests
- Dehydration (the only disease cause); recent IV albumin; prolonged tourniquet or standing draw; bromocresol green over-read
- Low Suggests
- Inflammation: sepsis, surgery, trauma, burns
- Cirrhosis
- Nephrotic syndrome or gut protein loss
- Capillary leak and dilution after large IV fluid volumes
- Act Now If
- Cirrhosis with ascites plus fever, abdominal pain, confusion or rising creatinine: suspect spontaneous bacterial peritonitis (SBP) or hepatorenal syndrome (HRS-AKI); monitor SpO₂ and urine output; notify receiving/medical control
- Watch Out For
- Low albumin hides danger: a normal anion gap can mask lactic acidosis or DKA, and low total calcium may be normal ionized calcium. Correct the gap; measure ionized Ca²⁺
Reference & Critical Ranges
Lab-specific ranges: Every lab sets its own interval, and the analyzer and the population change the number too. The range on your lab report wins. The values here are typical only.
Reference ranges
| Population | Conventional | SI | Notes |
|---|---|---|---|
| Adult | 3.5–5.0 g/dL | 35–50 g/L | Same for men and women. Some labs report 3.4–5.4 g/dL |
| Pregnancy | Lower than nonpregnant | — | Falls through gestation, lowest in the third trimester (hemodilution); recovers after delivery |
| Older adult | 3.5–5.0 g/dL | 35–50 g/L | No separate range. A low value usually reflects illness or inflammation, not age |
| Neonate (0–14 days) | 3.3–4.5 g/dL | 33–45 g/L | Approximate pediatric interval (bromocresol green method); use your lab's age-specific range |
| Infant (15 days–1 year) | 2.8–4.7 g/dL | 28–47 g/L | Widest range of childhood |
| Child (1–2 years) | 3.8–4.7 g/dL | 38–47 g/L | Older children and adolescents approach the adult range; use your lab's age-specific range |
Severity & critical values
| Level | Conventional | SI | What it means / typical findings |
|---|---|---|---|
| High | >5.0 g/dL | >50 g/L | Hemoconcentration, recent IV albumin or a collection artifact |
| Normal | 3.5–5.0 g/dL | 35–50 g/L | — |
| Low (hypoalbuminemia) | <3.5 g/dL | <35 g/L | Common in hospitalized patients; marks inflammation and severity of illness |
| Marked | <3 g/dL | <30 g/L | Albumin threshold in the Kidney Disease: Improving Global Outcomes (KDIGO) 2021 nephrotic syndrome definition. Infusing albumin to keep it above this level did not help hospitalized patients with decompensated cirrhosis |
| Very low | <2.5 g/dL (bromocresol green) or <2 g/dL (bromocresol purple or immunoassay) | <25 or <20 g/L | In membranous nephropathy and other high-risk nephrotic states, KDIGO's thrombosis-risk threshold (depends on the assay method), weighed against bleeding risk |
| Critical | No universal critical value | — | Interpret by trend and clinical context; act on the cause |
Critical values: There is no universal critical value. Read the trend and the clinical picture. The real danger is what a low albumin hides. Total calcium reads falsely low, and the anion gap reads falsely normal.
Conversion: g/dL × 10 = g/L
Albumin-corrected calcium
Corrected Ca (mg/dL) = measured total Ca + 0.8 × (4.0 − albumin in g/dL)
Check the result against your lab's total calcium range. Remember what it is: an estimate. It often misclassifies calcium status in critically ill and kidney patients. When the answer changes management, measure ionized calcium.
Albumin-corrected anion gap
Corrected anion gap = measured anion gap + 2.5 × (4.0 − albumin in g/dL)
Compare it with your lab's normal anion gap. Every 1 g/dL drop in albumin pulls the measured gap down by about 2.5 mEq/L.
Serum-ascites albumin gradient (SAAG)
SAAG = serum albumin − ascitic fluid albumin (g/dL, samples drawn at the same time)
A SAAG of ≥1.1 g/dL means portal hypertension, and it is about 97% accurate. Under 1.1 g/dL, look away from portal hypertension.
Causes of Abnormal Results
Low (hypoalbuminemia <3.5 g/dL)
| Mechanism | Common causes | Bedside clue |
|---|---|---|
| Inflammation (negative acute-phase response) | Sepsis, major surgery, trauma, burns; chronic inflammatory disease, cancer | Acute illness, high CRP. Albumin falls by about 1–1.5 g/dL after major surgery |
| Capillary leak and redistribution | Septic shock, major burns, critical illness | Edema and a positive fluid balance while the circulation still needs volume |
| Reduced liver synthesis | Cirrhosis and advanced chronic liver disease | Ascites, high INR and bilirubin, low platelets; falls over weeks, not hours |
| Kidney loss | Nephrotic syndrome (proteinuria >3.5 g/day) | Edema, frothy urine, 3+ to 4+ protein on dipstick, high cholesterol |
| Gut loss | Protein-losing enteropathy (inflammatory bowel disease, intestinal lymphatic obstruction) | Diarrhea or edema with little or no proteinuria |
| Skin and wound loss | Major burns, large open wounds | Large weeping surface area |
| Dilution | Large crystalloid volumes, pregnancy, blood drawn supine | Recent fluids; hemoglobin and other proteins fall in parallel |
| Very low protein intake | Severe, prolonged protein deficiency | Synthesis falls, but a normal albumin does not exclude malnutrition and a low one does not prove it |
Not a nutrition marker: Albumin is not a nutrition test. The American Society for Parenteral and Enteral Nutrition (ASPEN) says serum albumin (and prealbumin) reflects inflammation, not nutrition status or muscle mass. Never use a low albumin to diagnose or track malnutrition. Run a structured nutrition assessment instead.
High (hyperalbuminemia >5.0 g/dL)
Here's the catch with a high value: dehydration aside, no disease actually raises albumin. The number reflects concentration, an infusion or an artifact.
| Mechanism | Common causes | Bedside clue |
|---|---|---|
| Hemoconcentration | Dehydration (vomiting, diarrhea, poor intake) | Dry mucosa, high hematocrit and BUN; falls with rehydration |
| Exogenous albumin | Recent IV albumin, especially 20–25% | Infusion on the medication record; the result reflects the dose, not the patient |
| Collection artifact | Prolonged tourniquet; blood drawn standing | Hemoglobin, calcium and total protein also high |
| Assay over-read | Bromocresol green method (the dye also binds globulins) | Reads about 0.5 g/dL above immunoassay on the same sample |
Interpretation & Bedside Approach
Step-by-step approach
- Is it real? Look for dilution from recent fluids or a line draw, a supine draw, a recent albumin infusion and the assay method. Then compare with earlier results from the same lab.
- How sick is the patient? A low albumin marks inflammation and illness severity, and it predicts worse outcomes. That makes it a reason to look harder, not a number to chase.
- Acute or chronic, and the trend: Albumin's half-life is 15–20 days. A drop over hours to days points to dilution, capillary leak or inflammation, not new liver failure. The trend beats any single value.
- Calculate what it distorts: Correct the anion gap for albumin. Use corrected calcium only as a screen, and measure ionized calcium when it matters. Calculate the SAAG when ascites is tapped.
- Classify with named criteria: Check the urine protein. Per KDIGO 2021, adult nephrotic syndrome means proteinuria >3.5 g/day plus albumin <3 g/dL. In children, use a urine protein:creatinine ratio ≥2 mg/mg with low albumin or edema. Cut-offs vary by guideline, so check the current KDIGO pediatric guidance. In cirrhosis, albumin is an input to MELD 3.0 (Model for End-Stage Liver Disease), the US liver-allocation score since 2023.
- Escalate or dispose: Cirrhosis with ascites, plus fever, abdominal pain, confusion or rising creatinine, needs an SBP and AKI workup now. New nephrotic syndrome needs nephrology.
Pattern recognition
| Pattern | Suggests |
|---|---|
| Low albumin, high INR, low platelets, ascites | Cirrhosis with reduced synthetic function |
| Low albumin, 3+ to 4+ urine protein, edema, high cholesterol | Nephrotic syndrome; quantify with a urine protein:creatinine ratio |
| Low albumin, normal urine protein, chronic diarrhea | Protein-losing enteropathy or malabsorption |
| Abrupt fall in an ICU or postoperative patient, high CRP | Inflammation, capillary leak and dilution |
| SAAG ≥1.1 g/dL | Portal hypertension: cirrhosis, cardiac ascites (high ascitic protein), Budd-Chiari syndrome |
| SAAG <1.1 g/dL | Not portal hypertension: peritoneal carcinomatosis, tuberculous peritonitis, pancreatic ascites, nephrotic syndrome |
Low albumin hides acidosis: Your "normal" gap may be lying. Albumin carries most of the unmeasured anion. A gap of 12 mEq/L with albumin at 2 g/dL is really 17 mEq/L. Lactic acidosis, DKA or a toxic alcohol can sit behind that number.
Management Priorities
Treat the cause. The number is not the target. IV albumin has a few proven indications, and nearly all of them sit in cirrhosis. Never give it to lift a low level alone. Hospitals and ICUs run albumin and terlipressin. Prehospital crews do not. Your part is recognition, monitoring and handoff.
Emergency: Cirrhosis with ascites plus fever, abdominal pain, confusion or rising creatinine
- Recognize: suspect SBP and AKI; check vitals, SpO₂, mental status and urine output; notify receiving/medical control.
- Tap and treat (ED/ICU): diagnostic paracentesis and IV antibiotics without delay; give albumin per the table for SBP.
- Protect the kidneys: stop diuretics and nephrotoxins (including NSAIDs); assess volume status before any fluid.
- Monitor & repeat: creatinine and sodium daily, urine output hourly, lung sounds and SpO₂ with every albumin dose.
Medications
| Drug | Adult dose | Pediatric dose (max) | Onset / key notes |
|---|---|---|---|
| Albumin 20–25%: large-volume paracentesis (>5 L) | 6–8 g per liter of ascites removed IV, at the time of the tap (max 2 g/kg/day) | 25%: 0.5–1 g/kg IV, or 6–8 g per liter removed (max 2 g/kg/day) | Prevents post-paracentesis circulatory dysfunction and AKI; taps under 5 L usually need none. Pediatric data limited |
| Albumin 20–25%: SBP, with antibiotics | 1.5 g/kg IV within 6 hours of diagnosis, then 1 g/kg IV on day 3 (2 doses only; max 2 g/kg/day) | Not established in children: consult pediatric hepatology | Lowers kidney injury and mortality. Not for infections other than SBP (pneumonia, urinary): no benefit and more pulmonary edema |
| Albumin 20–25%: AKI in cirrhosis, volume status unclear | Fluid challenge 1–1.5 g/kg IV (Acute Disease Quality Initiative/International Club of Ascites, ADQI/ICA 2024); reassess creatinine and urine output at 24 hr (usual maximum 100 g/day; max 2 g/kg/day) | Not established in children: consult | No response in 24 hr and no other cause supports HRS-AKI; a fixed 48-hr albumin challenge is no longer required. Do not load overloaded patients |
| Albumin 20–25%: HRS-AKI, with a vasoconstrictor | 20–40 g/day IV, adjusted daily to volume status; stop for overload (titrate to volume status; max 2 g/kg/day) | Not established in children: consult; terlipressin is labeled for adults only | Terlipressin 0.85 mg IV every 6 hr is first line (label; reassess on day 4). ICU alternative: norepinephrine infusion High-alert |
| Albumin 5%: septic shock after large crystalloid volumes | 250–500 mL (12.5–25 g) IV; repeat after 15–30 min if needed (max 2 g/kg/day) | Not routinely used (consult): crystalloid, not albumin, for initial resuscitation | Surviving Sepsis Campaign (SSC) 2026 suggests crystalloids alone; albumin may be appropriate after large crystalloid volumes or with cirrhosis. Avoid with traumatic brain injury |
| Albumin: low serum albumin alone | Not indicated: do not give to raise the level | Not indicated | International Collaboration for Transfusion Medicine Guidelines (ICTMG) 2024: no benefit; repeated infusions to >3 g/dL in decompensated cirrhosis caused more serious adverse events, mainly pulmonary edema |
Terlipressin, norepinephrine and albumin: Watch the lungs. Respiratory failure is terlipressin's boxed warning, and extra volume makes it more likely. Check SpO₂ before you start, and do not start terlipressin if SpO₂ is <90%. Monitor continuously. At the first crackle, cut back or stop albumin. Labeling says to avoid terlipressin in ACLF grade 3, and benefit is unlikely with serum creatinine >5 mg/dL. It is contraindicated with ongoing coronary, peripheral or mesenteric ischemia. Deal with volume overload before and during use. Norepinephrine goes on a pump with an independent double-check.
Definitive care & disposition
- Cirrhosis with SBP, HRS-AKI or new ascites: Get hepatology input. Send to ICU for shock, or for terlipressin when hypoxia is a risk. Refer for transplant where appropriate. MELD 3.0 includes albumin.
- New nephrotic syndrome: Refer to nephrology and order a urine protein:creatinine ratio. In membranous nephropathy or another high-risk state, with albumin <2.5 g/dL by bromocresol green (or <2 g/dL by bromocresol purple or immunoassay), discuss prophylactic anticoagulation with nephrology. Weigh it against bleeding risk.
- ICU or postoperative hypoalbuminemia: Treat the cause. ICTMG 2024 does not suggest albumin in critically ill adults for first-line volume replacement, to raise the level, or alongside diuretics.
- Suspected malnutrition: Refer for a dietitian assessment. Albumin is not the measure.
Doses are typical references. Follow local protocols, medical direction and institutional policy.
Special Populations
| Population | What changes | Clinical implication |
|---|---|---|
| Neonates & infants | Lower and wider ranges in the first year (approximately 2.8–4.7 g/dL from 15 days to 1 year) | Use age-specific ranges. ICTMG 2024 does not suggest albumin for volume replacement in preterm neonates (≤32 weeks or ≤1,500 g) |
| Children & adolescents | Near adult values after infancy | Nephrotic syndrome is the classic cause of a very low value. In sepsis, give crystalloid rather than albumin for initial resuscitation (SSC 2026 children) |
| Pregnancy | Falls through gestation, lowest in the third trimester | Do not call a mildly low third-trimester value disease; total calcium falls with it, so use ionized calcium when calcium matters |
| Older adults | Same adult range | A low value reflects illness and inflammation and predicts worse outcomes; it is not a nutrition marker |
| CKD / dialysis | Assays disagree: bromocresol green reads high, bromocresol purple reads slightly low in hemodialysis (carbamylated albumin) | Trend on one method; the method shifts the nephrotic-syndrome and thrombosis thresholds. Corrected calcium is least reliable here |
| Liver disease | Reduced synthesis; albumin enters MELD 3.0 (bounded at 1.5–3.5 g/dL) | Scheduled albumin to keep levels >3 g/dL did not reduce infection, kidney dysfunction or death in hospitalized decompensated cirrhosis |
| Other: supine inpatients and ICU | Inflammation, capillary leak, dilution; supine draws read lower than ambulatory ranges | Compare like with like (same posture, same lab) |
Interfering Factors & Pitfalls
Collection & handling
| Factor | Effect | Why | Avoid / fix |
|---|---|---|---|
| Prolonged tourniquet | ↑ | Water leaves the occluded vein; proteins concentrate | Release promptly; redraw if prolonged |
| Posture | ↑ standing, ↓ supine | Standing shifts plasma water out of the vessels (plasma volume about 14% lower than supine) | Draw in a consistent posture; compare like with like |
| Draw from or above a running IV | ↓ | Dilution with infusate | Draw from the other arm or per line-sampling policy |
Medications & treatments
| Factor | Effect | Why | Avoid / fix |
|---|---|---|---|
| IV albumin | ↑ | Exogenous protein | Note infusion time; the level then reflects the dose |
| Large crystalloid volumes | ↓ | Dilution | Read against the fluid balance; hemoglobin falls too |
Assay & device-specific
| Factor | Effect | Why | Avoid / fix |
|---|---|---|---|
| Bromocresol green (BCG) method | ↑ (about 0.5 g/dL above immunoassay) | The dye also binds globulins | Know your lab's method; thresholds differ (2.5 g/dL by BCG ≈ 2 g/dL by BCP) |
| Bromocresol purple (BCP) in hemodialysis | ↓ (slight) | Carbamylated albumin binds the dye less | Trend on one method; ask the lab before comparing across sites |
Common misinterpretations
- "Low albumin means malnutrition": Wrong. It means inflammation or illness. Nutrition needs its own assessment.
- "Low albumin needs albumin": Raising the level gives no outcome benefit. Infusions add pulmonary edema risk.
- "Low total calcium means hypocalcemia": Check ionized calcium. Corrected calcium often misclassifies.
- "A normal anion gap rules out a gap acidosis": Correct the gap for albumin first, because low albumin can hide it.
Physiology & Test Basics
What it measures
This page covers serum (or plasma) albumin, the most abundant plasma protein and more than half of the total. Add globulins to albumin and you have total protein. Globulins and the albumin/globulin ratio get their own page: Total Protein. Do not confuse this with urine albumin (albuminuria), which is a different test.
Physiology & regulation
- Made only by the liver: about 10–15 g/day in an adult.
- Distribution: About 40% stays in the vessels. The rest sits in the interstitium of muscle, skin and fat.
- Slow turnover: Half-life is 15–20 days. That is why synthetic failure takes weeks to show.
- Oncotic pressure: About 70–80% of plasma colloid osmotic pressure comes from albumin.
- Carrier: It binds calcium, unconjugated bilirubin, fatty acids, hormones and many drugs.
- Negative acute-phase protein: Inflammation shifts the liver's priorities and opens capillaries. Levels fall.
How it is measured
- Specimen: serum (gold- or red-top tube) or lithium-heparin plasma (green top), per your lab. No fasting needed.
- Method: dye-binding on the chemistry analyzer: bromocresol green (BCG) or bromocresol purple (BCP). Immunoassay is more specific. BCG reads highest.
- Where it appears: comprehensive metabolic panel and hepatic function (liver) panel; laboratory test, not point of care.
Why it matters
Three readings shift because of albumin: total calcium, the anion gap and protein-bound drug levels. It also points toward cirrhosis and nephrotic syndrome, and the SAAG depends on it. A low number tells you about risk. It does not tell you what to treat.
Clinical Pearls
Correct the gap every time: Sick patient, albumin at 2 g/dL? Your "normal" gap of 12 mEq/L is really 17. Run lactate, ketones and the osmolal gap before you call it non-gap.
Order ionized calcium: The corrected number is an estimate, and it misreads many critically ill and kidney patients. Ionized calcium on a blood gas analyzer settles it in minutes.
Exam discriminator (CCRN, CFRN, FP-C): Cirrhosis plus SBP: antibiotics and albumin, since albumin keeps the kidneys from failing. Cirrhosis plus pneumonia or a urinary infection: antibiotics alone.
Cardiac ascites fools the gradient: Heart failure and constrictive pericarditis also push the SAAG high, the way cirrhosis does. The tell is ascitic total protein, which runs high here. Liver looks normal? Think heart.
Drug levels: Low albumin means a total phenytoin level understates the free (active) drug. Before you dose more for a "low" total, order a free level.
Transport handoff: For a cirrhosis patient, send the receiving team the newest albumin, creatinine, sodium and INR, each with its draw time. Add the liters of ascites drained and the grams of albumin given. While albumin runs, recheck lung sounds and SpO₂ after every move, and at altitude too.
References
- Callum, J., Skubas, N. J., Bathla, A., Keshavarz, H., Clark, E. G., Rochwerg, B., et al. (2024). Use of intravenous albumin: A guideline from the International Collaboration for Transfusion Medicine Guidelines. Chest, 166(2), 321–338. https://doi.org/10.1016/j.chest.2024.02.049
- Surviving Sepsis Campaign 2026 guidelines, adult and pediatric. Prescott, H. C., Antonelli, M., Alhazzani, W., Møller, M. H., et al. (2026). Surviving Sepsis Campaign: International guidelines for management of sepsis and septic shock 2026. Critical Care Medicine, 54(4), 725–812. https://doi.org/10.1097/CCM.0000000000007075; Weiss, S. L., Peters, M. J., Oczkowski, S. J. W., Belley-Cote, E., et al. (2026). Surviving Sepsis Campaign international guidelines for the management of sepsis and septic shock in children 2026. Pediatric Critical Care Medicine, 27(4), 379–434. https://doi.org/10.1097/PCC.0000000000003927
- Biggins, S. W., Angeli, P., Garcia-Tsao, G., Ginès, P., Ling, S. C., Nadim, M. K., Wong, F., & Kim, W. R. (2021). Diagnosis, evaluation, and management of ascites, spontaneous bacterial peritonitis and hepatorenal syndrome: 2021 practice guidance by the American Association for the Study of Liver Diseases. Hepatology, 74(2), 1014–1048. https://doi.org/10.1002/hep.31884
- Nadim, M. K., Kellum, J. A., Forni, L., Francoz, C., Asrani, S. K., et al. (2024). Acute kidney injury in patients with cirrhosis: Acute Disease Quality Initiative (ADQI) and International Club of Ascites (ICA) joint multidisciplinary consensus meeting. Journal of Hepatology, 81(1), 163–183. https://doi.org/10.1016/j.jhep.2024.03.031
- Kidney Disease: Improving Global Outcomes (KDIGO) Glomerular Diseases Work Group. (2021). KDIGO 2021 clinical practice guideline for the management of glomerular diseases. Kidney International, 100(4S), S1–S276. https://doi.org/10.1016/j.kint.2021.05.021
- Evans, D. C., Corkins, M. R., Malone, A., Miller, S., Mogensen, K. M., Guenter, P., & Jensen, G. L. (2021). The use of visceral proteins as nutrition markers: An ASPEN position paper. Nutrition in Clinical Practice, 36(1), 22–28. https://doi.org/10.1002/ncp.10588
- Kim, W. R., Mannalithara, A., Heimbach, J. K., Kamath, P. S., Asrani, S. K., Biggins, S. W., Wood, N. L., Gentry, S. E., & Kwong, A. J. (2021). MELD 3.0: The Model for End-Stage Liver Disease updated for the modern era. Gastroenterology, 161(6), 1887–1895.e4. https://doi.org/10.1053/j.gastro.2021.08.050
- Choy, K. W., Hickey, S., & Loh, T. P. (2026). A contemporary review of the limitations of adjusted calcium in clinical practice. Pathology, 58(2), 148–155. https://doi.org/10.1016/j.pathol.2025.08.010
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