What is an AST blood test. How does it help diagnose liver problems. What are normal AST levels. When should you get an AST test. How is the test performed. What do high AST levels indicate.

The Importance of AST in Liver Function Assessment

Aspartate aminotransferase (AST) is a crucial enzyme found predominantly in the liver, but also present in muscles and other organs. When cells containing AST are damaged, this enzyme is released into the bloodstream. An AST blood test measures the concentration of this enzyme in your blood, serving as a valuable indicator of liver health and potential organ damage.

AST tests are commonly used to:

• Assess overall liver function
• Diagnose liver damage or disease
• Monitor existing liver conditions
• Evaluate the effectiveness of liver treatments

Understanding AST levels can provide essential insights into your liver’s health and help healthcare providers make informed decisions about your treatment and care.

When Is an AST Blood Test Recommended?

Healthcare providers may order an AST blood test in various scenarios. These include:

1. As part of a routine health checkup
2. When liver damage is suspected
3. To monitor known liver conditions
4. Before starting medications that may affect liver function

Are there specific symptoms that warrant an AST test? Yes, several symptoms may prompt your doctor to order this test:

• Nausea and vomiting
• Loss of appetite
• Persistent fatigue
• Muscle weakness
• Jaundice (yellowing of skin and eyes)
• Abdominal pain or swelling
• Swollen ankles and legs
• Dark urine or light-colored stool
• Frequent itching

Even in the absence of symptoms, certain risk factors may necessitate regular AST testing. These include:

• Family history of liver disease
• Alcohol use disorder
• Obesity
• Diabetes
• Use of certain medications known to affect liver function
• History of hepatitis or potential exposure

The AST Blood Test Procedure: What to Expect

The AST blood test is a straightforward procedure that typically takes less than five minutes. Here’s what you can expect:

1. A healthcare professional will clean an area on your arm with an antiseptic.
2. A small needle will be inserted into a vein to draw a blood sample.
3. You may feel a slight sting as the needle enters and exits.
4. The blood is collected in a small vial or test tube.
5. Pressure is applied to the puncture site to stop any bleeding.
6. A bandage is placed over the area.

Is any special preparation required for an AST test? Generally, no specific preparation is needed for an AST blood test alone. However, since it’s often ordered alongside other blood tests, your healthcare provider may instruct you to fast for up to 12 hours before the test. Always follow your provider’s instructions carefully.

Interpreting AST Test Results: Normal Ranges and Implications

Understanding your AST test results is crucial for assessing liver health. Normal AST levels typically range from 10 to 40 units per liter (U/L) of blood. However, these ranges can vary slightly depending on the laboratory and the specific testing method used.

What do elevated AST levels indicate? High AST levels may suggest:

• Hepatitis (viral or alcoholic)
• Cirrhosis
• Mononucleosis
• Other liver diseases
• Heart problems
• Pancreatitis

It’s important to note that AST levels can be influenced by various factors, including age, sex, diet, and certain medications. Therefore, a single elevated AST result doesn’t necessarily indicate a medical condition requiring treatment. Your healthcare provider will interpret your results in the context of your overall health, symptoms, and other test results.

AST and ALT: A Comprehensive Liver Function Assessment

AST tests are often performed in conjunction with alanine transaminase (ALT) tests. ALT is another enzyme found primarily in the liver. The combination of AST and ALT tests provides a more comprehensive picture of liver health.

How do AST and ALT levels compare in liver assessment? In healthy individuals, ALT levels are typically higher than AST levels. When liver damage occurs, both enzymes may be elevated, but the ratio between them can provide valuable diagnostic information:

• An AST/ALT ratio greater than 2:1 may indicate alcoholic liver disease
• An AST/ALT ratio less than 1:1 is more common in viral hepatitis

These tests may be part of a larger panel of liver function tests that assess various aspects of liver health, including bilirubin levels, albumin, and prothrombin time.

Factors Affecting AST Levels: Beyond Liver Health

While AST is primarily associated with liver function, several other factors can influence its levels in the blood. Understanding these factors is crucial for accurate interpretation of test results:

• Muscle damage or intense exercise
• Heart conditions
• Certain medications
• Pregnancy
• Obesity
• Celiac disease

Can AST levels fluctuate naturally? Yes, AST levels can vary slightly from day to day and even throughout the day. This is why healthcare providers often consider trends in AST levels over time rather than relying on a single test result.

Managing High AST Levels: Lifestyle Changes and Treatment Options

If your AST levels are consistently elevated, your healthcare provider may recommend various strategies to improve liver health and reduce enzyme levels:

1. Limiting or avoiding alcohol consumption
2. Maintaining a healthy weight
3. Eating a balanced, liver-friendly diet
4. Regular exercise
5. Avoiding medications or supplements that may stress the liver
6. Managing underlying conditions like diabetes or heart disease

In some cases, specific treatments may be necessary to address the underlying cause of elevated AST levels. These could include antiviral medications for hepatitis, lifestyle changes for fatty liver disease, or other targeted therapies based on the diagnosed condition.

The Role of Diet in Liver Health and AST Levels

A healthy diet plays a crucial role in maintaining liver function and managing AST levels. Consider incorporating these liver-friendly foods into your diet:

• Leafy green vegetables
• Cruciferous vegetables like broccoli and Brussels sprouts
• Berries and other antioxidant-rich fruits
• Fatty fish high in omega-3 fatty acids
• Nuts and seeds
• Olive oil
• Green tea

Conversely, it’s advisable to limit or avoid:

• Processed foods high in sugar and unhealthy fats
• Excessive alcohol consumption
• Foods high in saturated fats
• Excessive salt intake

The Future of Liver Function Testing: Emerging Technologies and Approaches

While AST and ALT tests remain cornerstone assessments for liver health, researchers are continually developing new methods to enhance liver function evaluation. Some emerging technologies and approaches include:

• Non-invasive imaging techniques like FibroScan
• Genetic testing to identify liver disease risk factors
• Advanced blood tests that measure specific biomarkers of liver damage
• Artificial intelligence algorithms to interpret complex liver function data

How might these advancements impact liver health assessment? These new technologies could potentially provide earlier detection of liver problems, more precise diagnoses, and personalized treatment plans based on individual genetic and metabolic profiles.

The Importance of Regular Liver Health Monitoring

Regular monitoring of liver function, including AST levels, is crucial for maintaining overall health. This is particularly important for individuals with risk factors for liver disease or those taking medications that may affect liver function.

Consider discussing with your healthcare provider about the appropriate frequency of liver function tests based on your individual health profile and risk factors. Early detection of liver problems through regular monitoring can lead to more effective interventions and better long-term health outcomes.

In conclusion, understanding AST levels and their implications is an essential aspect of monitoring liver health. By staying informed about the factors that influence AST levels and working closely with healthcare providers, individuals can take proactive steps to maintain optimal liver function and overall well-being. Remember, liver health is a crucial component of overall health, and regular monitoring through tests like AST can play a significant role in preventive healthcare strategies.

AST Test: MedlinePlus Medical Test

What is an AST Test?

AST (aspartate aminotransferase) is an enzyme that is found mostly in the liver, but it’s also in muscles and other organs in your body. When cells that contain AST are damaged, they release the AST into your blood. An AST blood test measures the amount of AST in your blood. The test is commonly used to help diagnose liver damage or disease.

Other names: SGOT test, serum glutamic oxaloacetic transaminase test; aspartate transaminase test

What is it used for?

An AST blood test is often part of a routine blood screening to check the health of your liver. The test may help diagnose or monitor liver problems. It may also help diagnose other health conditions.

Why do I need an AST blood test?

You may get an AST blood test as part of your routine checkup or if you have symptoms of liver damage. These may include:

• Nausea and vomiting
• Lack of appetite
• Fatigue
• Weakness
• Jaundice, a condition that causes your skin and eyes to turn yellow
• Swelling and/or pain in your abdomen (belly)
• Swelling in your ankles and legs
• Dark-colored urine (pee) and/or light-colored stool (poop)
• Frequent itching

Even if you don’t have symptoms, your health care provider may order an AST blood test if you’re more likely to develop liver disease because of:

• A family history of liver disease
• Alcohol use disorder
• Obesity
• Diabetes
• Taking certain medicines that can cause liver damage
• Hepatitis or exposure to hepatitis

What happens during an AST blood test?

A health care professional will take a blood sample from a vein in your arm, using a small needle. After the needle is inserted, a small amount of blood will be collected into a test tube or vial. You may feel a little sting when the needle goes in or out. This usually takes less than five minutes.

Will I need to do anything to prepare for the test?

You don’t need any special preparations for an AST blood test. But an AST test is usually ordered with other blood tests. You usually need to fast (not eat or drink) for up to 12 hours before these tests. Your provider will let you know if there are any special instructions to follow.

Are there any risks to the test?

There is very little risk to having a blood test. You may have slight pain or bruising at the spot where the needle was put in, but most symptoms go away quickly.

What do the results mean?

High levels of AST in the blood may be a sign of hepatitis, cirrhosis, mononucleosis, or other liver diseases. High AST levels may also be a sign of heart problems or pancreatitis.

If your results are not in the normal range, it doesn’t always mean that you have a medical condition that needs treatment. Many things can affect your results, such as certain medicines and your age, sex, and diet. To learn what your results mean, talk with your provider.

Learn more about laboratory tests, reference ranges, and understanding results.

Is there anything else I need to know about an AST blood test?

Your health care provider may order an ALT blood test with your AST blood test. ALT stands for alanine transaminase, which is another type of liver enzyme. If you have high levels of AST and/or ALT, it may mean that you have some type of liver damage.

You may also have an AST test as part of a group of liver function tests that measure ALT, and other enzymes, proteins, and substances in the liver.

References

1. American Liver Foundation. [Internet]. New York: American Liver Foundation; c2017. Diagnosing Liver Disease – Liver Biopsy and Liver Function Tests; [updated 2020 Feb 17; cited 2022 Feb 14]; [about 3 screens]. Available from: https://liverfoundation. org/for-patients/about-the-liver/diagnosing-liver-disease/
2. Hinkle J, Cheever K. Brunner & Suddarth’s Handbook of Laboratory and Diagnostic Tests. 2nd Ed, Kindle. Philadelphia: Wolters Kluwer Health, Lippincott Williams & Wilkins; c2014. Aspartate Aminotransferase; p. 68–69.
3. National Heart, Lung, and Blood Institute [Internet]. Bethesda (MD): U.S. Department of Health and Human Services; Blood Tests; [cited 2022 Feb 14]; [about 15 screens]. Available from: https://www.nhlbi.nih.gov/health-topics/blood-tests
4. Testing.com [Internet]. Seattle (WA).: OneCare Media; c2022. Aspartate Aminotransferase: The Test; [modified 2021 Nov 9; cited 2022 Feb 14; [about 14 screens]. Available from: https://www.testing.com/test/aspartate-aminotransferase-ast/
5. University of Rochester Medical Center [Internet]. Rochester (NY): University of Rochester Medical Center; c2017. Health Encyclopedia: Aspartate Transaminase; [cited 2017 Mar 13]; [about 2 screens]. Available from: https://www. urmc.rochester.edu/encyclopedia/content.aspx?contenttypeid=167&contentid=aspartate_transaminase

Aspartate aminotransferase (AST) blood test Information | Mount Sinai

Aspartate aminotransferase; Serum glutamic-oxaloacetic transaminase; SGOT

The aspartate aminotransferase (AST) blood test measures the level of the enzyme AST in the blood.

Blood is drawn from a vein (venipuncture), usually from the inside of the elbow or the back of the hand. A needle is inserted into the vein, and the blood is collected in an air-tight vial or a syringe. Preparation may vary depending on the specific test.

How the Test is Performed

A blood sample is needed.

How to Prepare for the Test

No special preparation is needed.

How the Test will Feel

When the needle is inserted to draw blood, some people feel moderate pain. Others feel only a prick or stinging. Afterward, there may be some throbbing or a slight bruise. This soon goes away.

Why the Test is Performed

AST is an enzyme found in high levels in the liver, heart, and muscles. It is also found in lesser amounts in other tissues. An enzyme is a protein that causes a specific chemical change in the body.

Injury to the liver results in release of AST into the blood.

This test is mainly done along with other tests (such as ALT, ALP, and bilirubin) to diagnose and monitor liver disease.

Normal Results

The normal range is 8 to 33 U/L.

Normal value ranges may vary slightly among different laboratories. Some labs use different measurements or may test different samples. Talk to your health care provider about the meaning of your specific test results.

What Abnormal Results Mean

An increased AST level is often a sign of liver disease. Liver disease is even more likely when the levels of substances checked by other liver blood tests have also increased.

An increased AST level may be due to any of the following:

• Scarring of the liver (cirrhosis)
• Death of liver tissue
• Heart attack
• Too much iron in the body (hemochromatosis)
• Swollen and inflamed liver (hepatitis)
• Lack of blood flow to the liver (liver ischemia)
• Liver cancer or tumor
• Use of drugs that are toxic to the liver, especially alcohol use
• Mononucleosis (“mono”)
• Muscle disease or trauma
• Swollen and inflamed pancreas (pancreatitis)

AST level may also increase after:

• Burns (deep)
• Heart procedures
• Seizures
• Surgery

Pregnancy and exercise may also cause an increased AST level.

Risks

There is little risk involved with having your blood taken. Veins vary in size from one person to another and from one side of the body to the other. Taking blood from some people may be more difficult than from others.

Risks associated with having blood drawn are slight, but may include:

• Fainting or feeling lightheaded
• Excessive bleeding
• Multiple punctures to locate veins
• Hematoma (blood collecting under the skin)
• Infection (a slight risk any time the skin is broken)

Daniels L, Khalili M, Goldstein E, Bluth MH, Bowne WB, Pincus MR. Evaluation of liver function. In: McPherson RA, Pincus MR, eds. Henry’s Clinical Diagnosis and Management by Laboratory Methods. 24th ed. Philadelphia, PA: Elsevier; 2022:chap 22.

Pratt DS. Liver chemistry and function tests. In: Feldman M, Friedman LS, Brandt LJ, eds. Sleisenger and Fordtran’s Gastrointestinal and Liver Disease: Pathophysiology/Diagnosis/Management. 11th ed. Philadelphia, PA: Elsevier; 2021:chap 73.

Last reviewed on: 2/28/2023

Reviewed by: Jacob Berman, MD, MPH, Clinical Assistant Professor of Medicine, Division of General Internal Medicine, University of Washington School of Medicine, Seattle, WA. Also reviewed by David C. Dugdale, MD, Medical Director, Brenda Conaway, Editorial Director, and the A.D.A.M. Editorial team.

ALT and AST (blood chemistry)

ALT and AST – these abbreviations can often be seen in a blood test for biochemistry. What do they mean? What can they tell the doctor? Vasilisa Vladimirovna Ishchenko, a gastroenterologist at Clinic Expert Kursk, answers our questions.

ALT and AST – these abbreviations can often be seen in a blood test for biochemistry. What do they mean? What can they tell the doctor? Vasilisa Vladimirovna Ishchenko, a gastroenterologist at Clinic Expert Kursk, answers our questions.

– Vasilisa Vladimirovna, what do the abbreviations ALT and AST mean?

– ALT, or alanine aminotransferase, is an endogenous enzyme produced by liver cells – hepatocytes. Its content in blood serum is negligible. The highest concentration of ALT is observed in the liver, so this enzyme is a specific marker of diseases of this organ. In addition, small amounts of ALT can be found in the kidneys, heart muscle, skeletal muscles, and pancreas.

AST, or aspartate aminotransferase, is also an enzyme from the group of transaminases that is involved in amino acid metabolism. It is found mainly in the liver, myocardium, nervous tissue, skeletal muscles, and to a lesser extent in the kidneys, pancreas, spleen, and lung tissue.

When cells are damaged under the influence of infectious or toxic factors, energy metabolism in cells changes. Due to a violation of the permeability of cell membranes, components of the cytoplasm and decayed intracellular structures, including enzymes, enter the blood serum. As a result, the level of ALT and AST in the blood rises. This complex of disorders is called the cytolytic syndrome.

— What will the ALT and AST indicators tell about in a biochemical blood test?

— Normally, the concentration of transaminases and their ratio to each other in the blood plasma are constant values. They reflect the balance of formation and release of these enzymes. In addition, this balance indicates the normal course of the physiological destruction of aged cells (apoptosis). Deviation from the norm of the level of ALT and AST and a change in their ratio is observed in pathological processes.

The degree of increase in the activity of these enzymes allows us to judge the severity of the cytolytic syndrome. However, these indicators do not always indicate the severity of organ damage and do not allow the doctor to judge the prospects for the development of the disease. Therefore, along with the analysis of ALT and AST, specialists usually prescribe a set of laboratory and instrumental examination methods, and also monitor the level of enzymes in dynamics.

— When are these tests recommended?

– Data on the level of ALT and AST may be important for such non-specific symptoms as general weakness, decreased performance, lack of appetite, nausea, vomiting, abdominal pain, flatulence, yellowing of the skin and mucous membranes. These indicators are necessarily determined for the diagnosis of diseases and the assessment of the functioning of the liver.

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— What are the reasons for the increase in ALT and AST in the blood?

– Acute and chronic viral, toxic hepatitis, autoimmune diseases, fermentopathy, liver cirrhosis, tumor processes and liver metastases, infectious mononucleosis, pulmonary embolism, poliomyelitis, malaria, leptospirosis – in many pathological conditions, we observe an increase in the level of these enzymes in blood. Also, ALT and AST levels increase with myocardial infarction. Small short-term changes in their level can be observed during heavy physical exertion.

I would like to note that the ratio between ALT and AST (the so-called de Ritis coefficient) is also an important diagnostic indicator. This coefficient helps us distinguish, for example, viral hepatitis from alcoholic liver damage, myocardial infarction from liver disease.

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— What can cause a decrease in ALT and AST levels in the blood?

– Vitamin B6 deficiency, severe liver cirrhosis, pancreatic pathologies, renal failure (especially in patients on hemodialysis).

— How does the level of ALT and AST in the blood during pregnancy change?

– Since the liver during this period detoxifies the body of not only the mother, but also the fetus, an increase in the level of these enzymes can be observed.

— Vasilisa Vladimirovna, do you need to prepare for the test for ALT and AST? If so, which one?

– Definitely required. Blood from a vein must be taken in the morning on an empty stomach (the last meal 12 hours before the study). On the eve of the test, severe physical exertion, changes in diet, and the use of alcoholic beverages should be avoided. Half an hour before blood sampling, you should also refrain from smoking.

I want to emphasize that the determination of only the level of ALT and AST is not always informative enough, therefore, most often doctors prescribe them in combination with other biochemical indicators.

Would you like to read about other tests? You can find articles about them in our section on laboratory diagnostics

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Interviewed by Sevil Ibraimova

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For information:

Ishchenko Vasilisa Vladimirovna

Graduate of the Medical Faculty of Kursk State Medical University in 2015.

In 2016 she completed her internship in Therapy and underwent retraining in gastroenterology.

Currently holds the position of a gastroenterologist at the “Expert Clinic” Kursk. Conducts reception at the address: st. Karl Liebknecht, 7.

ALT and AST what is it?

ALT ( alanine aminotransferase) and AST (aspartate aminotransferase) – belong to aminotransferase enzymes involved in amino acid metabolism. They are also called liver enzymes. They are found mainly in the cells of the liver and in other organs: pancreas, heart, kidneys, muscle tissue. A small amount of ALT and AST may appear in the blood due to physiological processes. However, in case of liver diseases (infectious or toxic hepatitis, tumor), damage to the liver cells occurs, the permeability of cell membranes is impaired and a large amount of ALT and AST enzymes are released into the blood – as a result, a cytolytic syndrome develops.

ALT and AST transaminases are specific markers of liver disease. Indications for their appointment may be the following:

• Presence of symptoms: nausea, vomiting, abdominal pain, yellowing of the skin and sclera, lethargy.
• laboratory diagnostics of liver diseases: viral hepatitis A, B, C, toxic hepatitis, fatty non-alcoholic liver disease (steatohepatitis), alcoholic liver disease, cirrhosis of the liver.
• Monitoring the dynamics of therapy for liver diseases.

Norms for the content of liver enzymes in the blood:

Age	Men	Women	Units
0-1 years	13-45		U/ml
1-60 years old	10-40	7. 0-35.0
60-90 years old	13.0-40.0	10.0-28.0
Over 90 years old	6.0-38	5.0-24.0

Reasons for increasing ALT, AST (hepatic and extrahepatic)

The level of ALT in acute viral or drug-induced hepatitis can rise 50 times or more. With steatohepatitis and alcoholic liver disease, the increase in ALT is moderate – no more than 5 times. In chronic hepatitis, there is an increase in ALT by about 7 times. In cirrhosis, ALT and AST values ​​increase by 3-5 times, while AST may be higher than ALT.

During pregnancy, a woman’s body experiences an increased load, so there may be a slight increase in transaminases.

Currently, macro-AST-emia syndrome has become known – this is a rare condition in which complexes are formed in the human body from the AST molecule and immunoglobulin. This condition may be hereditary or associated with liver disease. It is characterized by a prolonged and asymptomatic increase in alanine aminotransferase in the blood.

An important diagnostic value is not only an increase in the level of transaminases, but also a decrease. A decrease in ALT and AST below normal indicates end-stage cirrhosis or severe liver damage in hepatitis. This is an extremely unfavorable sign, as it indicates the total destruction of liver cells.