AST Blood Test: Normal Ranges, High Levels, and Next Steps

If your AST (SGOT) blood test came back high or flagged abnormal, it can be hard to know whether it’s serious. Here’s how to interpret your number, what causes elevations, and when follow-up testing makes sense.

Dr. Alan Farrell

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July 14, 2026

6 min

AST, also called SGOT, is one of the core enzymes used to evaluate liver health. But unlike ALT, AST is also found in your heart, muscles, kidneys, and red blood cells. That means your AST result needs context to understand whether it’s reflecting liver stress, metabolic changes, or something as simple as a hard workout.

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Normal AST Ranges

ALT/AST Ranges by Group
Group	Optimal	Elevated	Highly Elevated	Very Highly Elevated
Men (U/L)	<45	46–90	91–1000	>1000
Women (U/L)	<35	36–70	71–1000	>1000

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Reference ranges vary by lab, age, and sex, so it’s always important to treat numberds a a guide, not universal. AST always needs to be interpreted alongside ALT, GGT, and the AST:ALT ratio to have a clear understanding of how your numbers impact your liver function.

Common Causes of High AST

A high AST result can come from both liver and non-liver sources because AST is found in the liver, muscles, heart and other tissues. An elevated result does not automatically mean you have liver disease.

AST is most useful when reviewed alongside ALT and other liver markers. Looking at the relationship between AST and ALT can provide more context about what may be affecting your results.

Liver-Related Causes

Liver cells can release AST into the bloodstream when they are stressed, inflamed or injured.

Metabolic dysfunction-associated steatotic liver disease, or MASLD
Alcohol-related liver stress
Viral hepatitis
Medication effects, including some statins and antibiotics
Acetaminophen use, including products such as Tylenol
Broader metabolic dysfunction

Non-Liver Causes

Because AST is also present in muscle and other tissues, some elevations may not originate in the liver.

Intense exercise during the previous 48 to 72 hours
Muscle strain or injury
Heart muscle stress or injury
Kidney-related health concerns
Hemolysis, or the breakdown of red blood cells

Why ALT matters: AST is typically interpreted alongside ALT because ALT is more closely associated with the liver. Reviewing both markers, along with their ratio and other liver results, can help distinguish liver-related changes from muscle-related causes.

What Does Low AST Mean?

A low AST level is rarely a clinical concern. For most people, it simply reflects a normal result and does not require treatment or additional testing.

Possible reasons for a low AST result include:

Normal enzyme levels, which is the most common explanation
Lower vitamin B6 intake
Lower muscle mass
Older age
Chronic kidney disease

Persistently low AST alongside symptoms may warrant a broader review of vitamin B6, kidney function and metabolic markers. For most people, however, a low AST result is considered normal.

How At-Home AST Testing Works

At-home liver testing makes it possible to measure AST and other liver-related biomarkers without visiting a traditional laboratory.

Collect your sample

Use the provided materials to collect a small finger-prick blood sample at home.

Mail it to the lab

Return your sample using the included prepaid mailing materials.

View your results

Review your biomarker results in your secure Choose Health dashboard.

Track changes

Compare future results to your baseline and monitor how your markers change over time.

Choose Your Level of Liver Testing

Both Choose Health liver tests include AST. The right option depends on whether you want a focused view of liver function or broader liver and metabolic insights.

Focused liver testing

Liver Function Test

$90 · 7 markers

Measure AST alongside six additional markers associated with liver health and function. This is the more focused option for establishing a liver baseline and monitoring changes over time.

View the Liver Function Test

Liver and metabolic testing

Comprehensive Liver Function Test

$165 · 20+ markers and metrics

Measure AST alongside ALT, GGT, bilirubin, glucose, insulin, HbA1c, cholesterol, iron markers and more for a broader view of liver and metabolic health.

View the Comprehensive Liver Test

Choose Health tests provide health information and are not a substitute for medical advice, diagnosis or treatment. Discuss elevated AST, persistent symptoms or other abnormal results with a qualified healthcare professional.

What to Do After You Receive Your AST Results

AST Results and What to Do
AST Result	What to Do
Normal AST	Track annually or as part of ongoing metabolic health monitoring.
Mildly Elevated AST	Avoid alcohol for several days; skip heavy workouts for 48–72 hours; review medications or supplements; retest in 2–4 weeks; check ALT and GGT for supporting patterns.
Significantly Elevated AST	Review the full liver panel; evaluate the AST:ALT ratio; speak with a clinician (Choose Health telehealth available); consider imaging or additional testing.
Low AST	Usually normal; check vitamin B6 intake if diet is limited; follow up only if symptoms or other abnormal markers are present.

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Frequently Asked Questions About AST

Common questions about what AST measures, what can affect your results and when retesting may be useful.

What is AST in a blood test?

AST, or aspartate aminotransferase, is an enzyme found in the liver, muscles, heart and other tissues. An AST blood test measures how much of the enzyme is present in your bloodstream. Higher levels can occur when liver or muscle cells are stressed, inflamed or injured.

What is SGOT or AST in a blood test?

SGOT stands for serum glutamic-oxaloacetic transaminase. It is the older name for AST. SGOT and AST refer to the same enzyme and the same blood test, although most laboratories now use the term AST.

Does high AST always mean liver disease?

No. AST is not found only in the liver. Strenuous exercise, muscle injury, alcohol use, certain medications and other health conditions can also raise AST levels. AST is usually interpreted alongside ALT and other test results to help identify the most likely source.

What does a low AST level mean?

A low AST result is usually considered normal and is generally not a cause for concern. Your result should still be reviewed in the context of the laboratory’s reference range and your other blood markers.

How often should I check my AST level?

For general health monitoring, AST may be checked during routine blood testing once or twice a year. More frequent testing may be appropriate if you have liver or metabolic risk factors, take medications that can affect the liver or are monitoring a previously abnormal result. A healthcare professional can recommend a testing schedule based on your individual health history.

AST results should not be interpreted alone. ALT, GGT, bilirubin and other liver markers can provide additional context about what may be affecting your result.

Summary

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The AST blood test is a valuable marker of liver and metabolic health, but it must be interpreted with context. Because AST is found in many tissues, the real insights come from reviewing it alongside ALT, GGT, inflammation markers, and metabolic indicators.

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Curious about where your liver stands? Take 5 minutes to explore your liver's health score below!

Liver Health Quiz