De Ritis Ratio (AST/ALT) Biomarker Testing
It compares AST to ALT to add context to liver enzyme results and possible causes, with easy ordering and Quest-based lab draws via Vitals Vault.
With Vitals Vault, you have access to a comprehensive range of biomarker tests.
The De Ritis ratio is a simple calculation that compares two common liver enzymes: AST (aspartate aminotransferase) divided by ALT (alanine aminotransferase). You will usually see it discussed when one or both enzymes are outside the lab’s reference range and you want more context than a single number can provide.
Because AST can come from liver and muscle (and a few other tissues), while ALT is more liver-focused, the ratio can sometimes hint at whether a pattern looks more “liver-predominant” or whether something outside the liver could be contributing.
Your ratio is not a diagnosis by itself. It works best when you interpret it alongside the actual AST and ALT values, your symptoms, medications, alcohol intake, exercise, and other labs your clinician may order.
Do I need a De Ritis Ratio test?
You may want a De Ritis ratio when your AST and/or ALT are elevated and you are trying to understand what the pattern could mean. This comes up often after routine screening labs, during evaluation of fatigue, right-upper-abdominal discomfort, nausea, unexplained itching, dark urine, or yellowing of the eyes or skin.
It can also be useful if you have risk factors for liver stress, such as higher alcohol intake, metabolic risk (insulin resistance, higher triglycerides, or central weight gain), known fatty liver, viral hepatitis exposure, or use of medications that can affect the liver. If you recently did intense exercise, had muscle injury, or have a muscle condition, the ratio may help frame whether AST could be coming from muscle rather than liver.
You do not usually order this ratio “alone.” Most of the time it is calculated from AST and ALT that are already part of a hepatic function panel (liver panel) or a comprehensive metabolic panel (CMP). Testing supports clinician-directed care and follow-up planning, not self-diagnosis.
The De Ritis ratio is a derived value calculated from AST and ALT measured in a CLIA-certified laboratory; it is not a standalone diagnostic test.
Lab testing
Order labs that include AST and ALT to calculate your De Ritis ratio.
Schedule online, results typically within about a week
Clear reporting and optional clinician context
HSA/FSA eligible where applicable
Get this test with Vitals Vault
With Vitals Vault, you can order labs that include AST and ALT and then use your results to calculate (and discuss) the De Ritis ratio in context. This is helpful when you want a clear next step after an “abnormal liver enzyme” alert or when you are tracking whether a change in lifestyle, medication, or alcohol intake is moving your labs in the right direction.
After your results are in, PocketMD can help you understand what a low, typical, or high ratio may suggest, which follow-up labs are commonly paired with AST/ALT, and what details to bring to your clinician. If a repeat test is appropriate, you can reorder and trend results over time.
If you already have AST and ALT from a recent draw, you can still use PocketMD to interpret the ratio and decide whether additional testing (for example, bilirubin, alkaline phosphatase, GGT, CK, or hepatitis screening) would make your follow-up more complete.
- Order online and draw at a participating lab location
- Clear result context with PocketMD guidance
- Easy retesting to track trends over time
Key benefits of De Ritis Ratio testing
- Adds context to elevated AST and ALT instead of treating each enzyme in isolation.
- Helps you and your clinician consider whether AST could be influenced by muscle stress or injury.
- Supports pattern-based follow-up (for example, pairing with bilirubin, ALP, and GGT when cholestasis is a concern).
- Can be useful for monitoring changes after reducing alcohol intake or adjusting medications that affect the liver.
- Helps prioritize repeat testing timing when a transient trigger (like hard exercise) may have skewed AST.
- Encourages a fuller liver-risk review, including metabolic health, viral hepatitis risk, and medication/supplement exposures.
- Makes it easier to track and discuss trends over time when you repeat the same core liver enzymes.
What is De Ritis Ratio?
The De Ritis ratio is the AST/ALT ratio: your AST value divided by your ALT value. Both AST and ALT are enzymes involved in amino acid metabolism, and they can leak into the bloodstream when cells are stressed or injured.
ALT is found mainly in liver cells, so it is often considered more specific to liver injury. AST is found in the liver too, but it is also present in skeletal muscle, heart muscle, kidneys, brain, and red blood cells. That broader distribution is why AST can rise for reasons that are not primarily liver-related.
The ratio does not replace looking at the absolute numbers. A ratio can look “high” even when both enzymes are normal, and that is usually not meaningful. The ratio becomes most informative when at least one of the enzymes is elevated and you interpret it alongside your history and other labs.
How the ratio is typically interpreted
Many clinicians think of a ratio around 1 as a common pattern when AST and ALT rise together. Ratios below 1 often reflect ALT being higher than AST, which can be seen in several liver conditions. Ratios above 1 mean AST is higher than ALT, which may occur with alcohol-related liver injury, more advanced liver scarring in some settings, or non-liver sources of AST such as muscle injury.
Why the ratio can be misleading
Because AST can increase after strenuous exercise, muscle trauma, or hemolysis (breakdown of red blood cells), a high ratio does not automatically mean liver disease. Medications, lab timing, and recent illness can also shift AST and ALT. This is why follow-up often includes repeat testing and companion markers like bilirubin, alkaline phosphatase (ALP), gamma-glutamyl transferase (GGT), and creatine kinase (CK).
What do my De Ritis Ratio results mean?
Low De Ritis ratio (AST/ALT below your lab’s typical pattern)
A lower ratio usually means ALT is higher than AST. This pattern can be seen when liver cell irritation is more prominent, because ALT is more concentrated in the liver. If your ALT is elevated, your clinician may look for common drivers such as fatty liver related to metabolic risk, medication effects, viral hepatitis, or recent infection. A low ratio is most meaningful when AST and/or ALT are actually above range; if both are normal, the ratio alone rarely changes next steps.
Typical or in-range De Ritis ratio
A ratio near 1 is a common finding, especially when AST and ALT are both within the reference range. If your enzymes are normal and you feel well, this usually supports routine monitoring rather than urgent follow-up. If your enzymes are elevated but the ratio is near 1, your clinician will usually rely more on the degree of elevation and other liver markers (bilirubin, ALP, GGT) to decide what to do next.
High De Ritis ratio (AST/ALT above your lab’s typical pattern)
A higher ratio means AST is higher than ALT. This can happen with alcohol-related liver injury, and it can also be seen in some cases of more advanced liver disease where ALT production falls as liver cell mass declines. Just as importantly, a high ratio can reflect non-liver AST sources, such as recent intense exercise, muscle injury, or muscle disease. If your ratio is high, it is often helpful to review recent workouts, injuries, and medications, and to consider add-on tests like CK and GGT to clarify the source.
Factors that influence the De Ritis ratio
Recent strenuous exercise, muscle trauma, or intramuscular injections can raise AST and push the ratio higher. Alcohol intake can shift the pattern toward higher AST relative to ALT, especially when combined with other liver stressors. Certain medications and toxins can raise either enzyme, and timing matters because AST and ALT rise and fall at different rates after an injury. Hemolysis during blood draw or underlying hemolytic conditions can also increase AST, which is one reason repeat testing is sometimes recommended when results do not match how you feel.
What’s included
Frequently Asked Questions
What is a normal De Ritis ratio (AST/ALT ratio)?
Many people have a ratio around 1 when AST and ALT are both normal, but “normal” is not a single universal cutoff. The ratio is most useful when at least one enzyme is elevated, and your clinician interprets it alongside the absolute AST and ALT values and your clinical context.
Can exercise raise my De Ritis ratio?
Yes. Hard workouts, especially strength training or endurance events, can raise AST from muscle and make the ratio look higher. If your result does not fit your symptoms or history, repeating labs after a few days of lighter activity is a common approach, and CK may be added to assess muscle contribution.
Does a high AST/ALT ratio mean alcohol-related liver disease?
A higher ratio can be seen with alcohol-related liver injury, but it is not specific enough to diagnose it. Muscle injury, hemolysis, and some liver conditions can also raise the ratio. A careful history plus other labs (often GGT, bilirubin, ALP, and sometimes imaging) is usually needed to clarify the cause.
Should I fast for a De Ritis ratio test?
Fasting is not typically required for AST and ALT. However, if your blood draw is part of a broader panel that includes lipids or glucose/insulin testing, fasting instructions may apply to those components. Follow the instructions provided with your order.
How often should I recheck AST, ALT, and the De Ritis ratio?
Retesting depends on how abnormal your enzymes are and what might be driving them. If there is a likely temporary trigger (like illness, alcohol, or intense exercise), your clinician may suggest repeating in a few weeks. If you are monitoring a known condition or medication effect, the interval may be shorter or longer based on your plan.
What other tests are commonly ordered with AST and ALT?
Common companions include bilirubin, alkaline phosphatase (ALP), and GGT to look at different patterns of liver injury, plus albumin and INR in some situations to assess liver function. If muscle contribution is possible, CK is often helpful. Hepatitis screening may be considered based on risk factors and the degree/pattern of elevation.