--- title: "Fatty Liver Disease: Which Blood Tests Identify It?" type: condition url: "https://www.test-well.com/conditions/fatty-liver" date_published: 2026-05-19 date_modified: 2026-07-13 reviewed_at: 2026-09-14 --- # Fatty Liver Disease: Which Blood Tests Identify It? *Non-alcoholic fatty liver disease (now called MASLD) affects an estimated 25-30% of US adults — most unknowingly. It's the most common chronic liver condition and a major precursor to type 2 diabetes and cardiovascular disease. The right blood tests catch it early.* > The Liver Health Panel ($59.99) covers the core: ALT, AST, GGT, alkaline phosphatase, bilirubin, total protein, albumin. Add fasting insulin + A1c (metabolic side) + Lipid Panel + hs-CRP for the complete fatty liver workup. ALT/AST elevation + metabolic syndrome features (high A1c, high insulin, abdominal obesity, high triglycerides, low HDL) strongly suggests MASLD. Diagnostic confirmation typically requires imaging (FibroScan or MRI elastography). ## Recommended tests | Recommended | Type | Price | Why | | --- | --- | --- | --- | | [Liver Health Panel](https://www.test-well.com/tests/liver-health-panel) | Panel (4 tests) | $59.99 | Liver health panel covering all standard liver enzymes — recommended | | [ALT (Alanine Aminotransferase)](https://www.test-well.com/tests/alt) | Test | $18.99 | Most specific routine liver enzyme; elevation is the headline finding in fatty liver | | [GGT (Gamma-Glutamyl Transferase)](https://www.test-well.com/tests/ggt) | Test | $19.99 | Gamma-Glutamyl Transferase — second liver enzyme, often elevated in fatty liver | | [Comprehensive Metabolic Panel](https://www.test-well.com/tests/comprehensive-metabolic-panel) | Test | $22.99 | Comprehensive Metabolic Panel — bundles ALT, AST & alkaline phosphatase with glucose and kidney markers | | [Diabetes Screening Panel](https://www.test-well.com/tests/diabetes-screening-panel) | Panel (3 tests) | $59.99 | Metabolic side — insulin resistance underlies most MASLD | | [Lipid Panel](https://www.test-well.com/tests/lipid-panel) | Test | $24.99 | Triglycerides + HDL pattern correlates with fatty liver | | [Hemoglobin A1c](https://www.test-well.com/tests/hemoglobin-a1c) | Test | $21.99 | Pre-diabetes/diabetes coexists with fatty liver in most cases | | [Insulin, Fasting](https://www.test-well.com/tests/insulin-fasting) | Test | $22.99 | Insulin resistance is the central mechanism | | [Heart & Body Inflammation Test (hs-CRP)](https://www.test-well.com/tests/hs-crp) | Test | $34.99 | Systemic inflammation marker — often elevated in active fatty liver | | [Ferritin](https://www.test-well.com/tests/ferritin) | Test | $24.99 | Iron overload syndromes can mimic fatty liver; ferritin also rises with NAFLD activity | All prices are cash-pay plus one $6 lab processing fee per order; physician authorization is included. ## What Fatty Liver Disease Actually Is Fatty liver disease — formally renamed Metabolic dysfunction-Associated Steatotic Liver Disease (MASLD) in 2023, previously called Non-Alcoholic Fatty Liver Disease (NAFLD) — is the accumulation of excess fat (steatosis) in liver cells. It's the most common chronic liver disease worldwide, affecting an estimated 25-30% of US adults and rising sharply with the obesity and metabolic syndrome epidemics. Most people who have it don't know. MASLD exists on a spectrum: - **Simple steatosis (fatty liver alone)** — fat accumulation without significant inflammation or damage. Generally considered relatively benign but a precursor to more advanced disease. - **MASH (formerly NASH — Non-Alcoholic Steatohepatitis)** — fatty liver PLUS active inflammation and liver cell damage. Progresses to fibrosis and cirrhosis in a significant subset of patients. - **Advanced fibrosis (F3) and cirrhosis (F4)** — scarring of the liver. End-stage liver disease, liver cancer (hepatocellular carcinoma), and need for liver transplantation are all possible outcomes. The connection to metabolic health: MASLD is essentially the liver manifestation of insulin resistance and metabolic syndrome. Roughly 70-80% of people with type 2 diabetes have MASLD. The relationship is bidirectional — MASLD increases diabetes risk; diabetes accelerates MASLD progression. MASLD also independently increases cardiovascular disease risk by 1.5-2x. Why most cases go undiagnosed: routine bloodwork often shows only mildly elevated liver enzymes (ALT, AST), which doctors frequently dismiss as "mild elevation, no action needed." The reality is that ALT above the modern thresholds (>33 IU/L for men, >25 IU/L for women — lower than older lab reference ranges) is a meaningful signal of liver injury, especially in someone with metabolic risk factors. Diagnostic confirmation typically requires imaging (FibroScan, MRI elastography) and sometimes biopsy in advanced cases — but blood markers catch the initial suspicion. **Who should consider fatty liver screening:** - Type 2 diabetes or pre-diabetes (70-80% have MASLD) - Obesity (BMI ≥30) or abdominal obesity (waist >40 inches men, >35 women) - Metabolic syndrome features: high triglycerides, low HDL, high blood pressure, abdominal obesity - PCOS (polycystic ovary syndrome) — closely associated with MASLD - Family history of fatty liver or liver disease - Persistent ALT or AST elevation on routine bloodwork - Unexplained fatigue + elevated metabolic markers ## The Core Fatty Liver Blood Workup **Liver enzymes (ALT, AST, GGT, alkaline phosphatase).** The headline markers for fatty liver workup. - **ALT (Alanine Aminotransferase)** — the most liver-specific enzyme. Modern healthy thresholds: <33 IU/L for men, <25 IU/L for women. Many labs still use older reference ranges (up to 40-55) that miss early disease. Elevation suggests liver cell damage; in MASLD, typically mild to moderate (1-3x upper limit of normal). - **AST (Aspartate Aminotransferase)** — less liver-specific (also present in heart, muscle, RBCs). In MASLD, AST is typically equal to or lower than ALT (AST/ALT ratio 2 suggests alcoholic liver disease rather than MASLD; AST/ALT ratio >1 in someone with MASLD suggests progression to fibrosis. - **GGT (Gamma-Glutamyl Transferase)** — sensitive to alcohol use, medications, and biliary issues. In MASLD, GGT is often elevated alongside ALT. Markedly elevated GGT (without proportional ALT) suggests alcohol or biliary causes rather than MASLD. - **Alkaline phosphatase + bilirubin** — typically normal in early MASLD. Elevation suggests biliary involvement or more advanced disease. The Liver Health Panel ($59.99) covers all of these in one order. **Platelets.** Included in CBC. Critical for the FIB-4 calculation (see below). Decreased platelet count can indicate advanced fibrosis or portal hypertension. **Albumin and bilirubin.** Generally normal in early MASLD. Decreased albumin or elevated bilirubin can indicate more advanced disease. **FIB-4 calculation.** A non-invasive score that estimates likelihood of significant fibrosis using age + ALT + AST + platelet count. Formula: `(Age × AST) / (Platelets × √ALT)`. Interpretation: - **FIB-4 <1.3** — low risk of advanced fibrosis (excellent negative predictive value) - **FIB-4 1.3-2.67** — indeterminate; consider FibroScan or other non-invasive imaging - **FIB-4 >2.67** — high probability of advanced fibrosis; warrants hepatology referral FIB-4 is used by hepatologists as a first-line non-invasive screen for fibrosis risk. You can calculate yours from a standard CBC + Liver Health Panel. **Metabolic workup (A1c + Fasting Glucose + Fasting Insulin + Lipid Panel).** The Diabetes Screening Panel ($59.99) + Lipid Panel covers this. MASLD is essentially insulin resistance manifesting in the liver — characterizing the metabolic side is essential. Pattern that suggests MASLD: elevated fasting insulin, A1c trending toward pre-diabetic range (5.5+), high triglycerides (often above 150 mg/dL), low HDL (below 40 men / 50 women), often elevated ApoB. **hs-CRP.** Systemic inflammation marker. Often elevated in active MASH (the inflammatory form of MASLD). **Ferritin.** Can be elevated in MASLD (often called "hyperferritinemia of metabolic syndrome"). Important to distinguish from hereditary hemochromatosis (iron overload disease) — usually requires transferrin saturation to differentiate. ## Ruling Out Other Liver Conditions Before concluding "fatty liver" from elevated liver enzymes, several other causes need to be considered: **Alcohol-related liver disease.** If you drink moderately or more, alcohol may be contributing. The threshold for alcohol-related fatty liver is generally considered >30g/day for men (about 2 standard drinks) or >20g/day for women (about 1.5 standard drinks). The diagnostic distinction matters because treatment differs. Honest discussion with your doctor is essential — many patients underreport alcohol use and end up labeled with MASLD when alcohol contribution is significant. Note: MASLD and alcohol-related liver disease can coexist (called MetALD — Metabolic and Alcohol-related Liver Disease). **Viral hepatitis.** Hepatitis B and C cause chronic liver inflammation and can mimic or coexist with MASLD. The Hepatitis Panel covers screening for both. Recommended at least once for everyone (CDC guidelines as of 2020 recommend universal screening for hepatitis B and C in all adults). **Autoimmune hepatitis.** Less common but important. ANA, anti-smooth muscle antibody, and anti-LKM-1 antibody are the screening markers. More common in women. **Hemochromatosis (iron overload).** Genetic condition causing iron accumulation in organs including liver. Screen with ferritin (elevated) + transferrin saturation (typically >45%). Genetic testing for HFE mutations confirms. **Wilson disease (copper overload).** Rare, typically presents in younger patients. Screen with ceruloplasmin (low in Wilson disease). **Alpha-1 antitrypsin deficiency.** Rare genetic condition. Screen with alpha-1 antitrypsin level if other causes are excluded. **Medication-induced.** Many medications can elevate liver enzymes — statins (usually mild and not requiring discontinuation), antibiotics, acetaminophen overuse, many others. Review medications with your prescriber. This is why elevated liver enzymes always warrant a complete workup rather than jumping to "must be fatty liver." A liver-focused primary care doctor or hepatologist can work through the differential systematically. ## Treatment and Monitoring **The good news:** MASLD is one of the most modifiable chronic diseases. Lifestyle intervention frequently reverses both fat accumulation and inflammation, especially in earlier stages. **The first-line treatment is weight loss + diet + exercise:** - **Weight loss of 5-10% body weight** can reduce liver fat by 30-40% and resolve simple steatosis in many cases. Weight loss of 10%+ can reverse some fibrosis. - **Dietary patterns that help:** Mediterranean diet has the most evidence specifically for MASLD. Lower carbohydrate diets also help by reducing the insulin signaling that drives liver fat storage. Reducing fructose (especially from high-fructose corn syrup in sugary drinks) is particularly important — fructose is preferentially converted to liver fat. - **Exercise:** both aerobic and resistance exercise independently reduce liver fat. Combined is best. Even 150 min/week of moderate exercise has measurable effects. - **Alcohol elimination or significant reduction.** **Medications:** - **Resmetirom (Rezdiffra)** — FDA-approved in 2024 specifically for MASH with significant fibrosis. The first MASLD-specific medication. - **GLP-1 medications (semaglutide, tirzepatide)** — increasingly used; significant evidence for reducing liver fat and improving MASH. Often appropriate for patients with both MASLD and obesity or diabetes. - **Vitamin E (800 IU/day)** — has evidence in non-diabetic adults with MASH; less benefit in diabetics. - **Statins** — safe to use in MASLD (do not avoid them due to mild liver enzyme elevation); may improve liver outcomes independent of cholesterol effects. - **Pioglitazone** — diabetes medication with evidence for improving MASH; balanced against side effects (weight gain, fluid retention). **Monitoring:** - **Annual liver enzymes + FIB-4 calculation.** Track trend over time. - **Annual A1c, lipid panel, fasting insulin.** Metabolic markers tend to move in parallel with liver markers. - **FibroScan or MRI elastography** every 2-3 years if FIB-4 is indeterminate or if there's concern about progression. These imaging tests measure liver stiffness (a proxy for fibrosis) noninvasively. - **Liver biopsy** only in selected advanced cases — increasingly avoided in favor of imaging. - **Hepatology referral** if FIB-4 >2.67, if FibroScan shows significant fibrosis, or if liver enzymes are markedly elevated or worsening despite treatment. ## Frequently asked questions ### My ALT is mildly elevated. Should I be worried? It depends on the context. Mildly elevated ALT (say, 50-80 IU/L) in someone with metabolic syndrome features (overweight, pre-diabetes, high triglycerides) is highly suggestive of fatty liver disease and warrants investigation — not dismissal. The right next steps: (1) Repeat in 4-8 weeks to confirm it's persistent, not a one-off blip from exercise or medications. (2) Calculate FIB-4 from your CBC + Liver Panel. (3) Address modifiable contributors: weight, diet, alcohol, certain medications. (4) Consider FibroScan or hepatology referral if FIB-4 is elevated or enzymes remain elevated despite intervention. Don't accept 'mild ALT elevation, no action' without at least an FIB-4 calculation and metabolic workup. ### I don't drink alcohol — how can I have 'non-alcoholic' fatty liver disease? MASLD (the newer name) more accurately captures the cause: it's driven by metabolic dysfunction, not alcohol. The OLD name 'NAFLD' (non-alcoholic fatty liver disease) was a name of exclusion — what's left after ruling out alcohol. The mechanism is insulin resistance: when cells become less responsive to insulin, the pancreas produces more, and elevated insulin promotes fat storage in the liver. Diets high in refined carbohydrates and fructose (especially from sweetened beverages) accelerate this. Genetics (PNPLA3 variant especially) increase susceptibility. So yes, non-drinkers absolutely get fatty liver — most cases of MASLD are in non-drinkers or moderate drinkers. ### Can I reverse fatty liver disease? Yes, especially in earlier stages. Simple steatosis (fat without inflammation) is highly reversible with weight loss and lifestyle change — 5-10% weight loss typically resolves it. MASH (the inflammatory form) is also reversible in many cases but requires more sustained intervention. Even early fibrosis can regress with significant weight loss (10%+) and metabolic improvement. Advanced fibrosis and cirrhosis are less reversible but progression can be halted. The takeaway: catching MASLD early and addressing it makes a meaningful difference in long-term outcomes. ### Should I get a FibroScan? FibroScan (transient elastography) is a non-invasive imaging test that measures liver stiffness, which correlates with fibrosis. It's increasingly used as a first-line screen for fibrosis severity, replacing the need for biopsy in many cases. Reasonable to pursue if: (1) Your FIB-4 score is indeterminate (1.3-2.67) and you want a more definitive assessment; (2) You have known MASLD and want to track fibrosis progression over time; (3) Your liver enzymes are elevated and you want to characterize disease stage before treatment decisions. Available through most hepatology offices and some imaging centers. Typically not in routine primary care. Insurance coverage variable — typically covered with appropriate clinical indication (elevated FIB-4, known MASLD, persistent ALT elevation). ### Will my insurance cover fatty liver screening? Basic liver enzymes (ALT, AST, GGT, alkaline phosphatase, bilirubin) are routinely included in standard annual physicals and well-covered by insurance. The Liver Panel is also typically covered with documented symptoms or risk factors. Comprehensive screening (adding fasting insulin, expanded metabolic markers, FibroScan) is more variably covered. Cash-pay through TestWell often makes sense for comprehensive workups. Total cost for the recommended fatty liver workup (Liver Panel + Diabetes Screening Panel + Lipid Panel + hs-CRP + Ferritin) is reasonable through DTC labs versus the equivalent through insurance billing. --- Medically reviewed by Youmna DiStefano, MD (Medical Reviewer, TestWell); last reviewed 2026-09-14. Review policy: https://www.test-well.com/reviewers/youmna-distefano-md Canonical page: https://www.test-well.com/conditions/fatty-liver Machine-readable catalog: https://www.test-well.com/api/catalog.json · MCP server: https://www.test-well.com/mcp · Overview for agents: https://www.test-well.com/llms.txt Prices are cash-pay, in USD, and include physician authorization; every order adds one flat $6 lab processing fee. Educational content is not a diagnosis — discuss results with a clinician.