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What is normal alt blood test: High vs. Low Levels, Direct vs. Indirect

High vs. Low Levels, Direct vs. Indirect

Written by WebMD Editorial Contributors

  • Why Do You Get This Test?
  • What Happens During the Test?
  • Who Should Get It? Who Shouldn’t?
  • What Do the Results Mean?

A bilirubin test measures the amount of bilirubin in your blood. It’s used to help find the cause of health conditions like jaundice, anemia, and liver disease.

Bilirubin is an orange-yellow pigment that occurs normally when part of your red blood cells break down. Your liver takes the bilirubin from your blood and changes its chemical make-up so that most of it is passed through your poop as bile.

If your bilirubin levels are higher than normal, it’s a sign that either your red blood cells are breaking down at an unusual rate or that your liver isn’t breaking down waste properly and clearing the bilirubin from your blood.

Another option is that there’s a problem somewhere along the pathway that gets the bilirubin out of your liver and into your stool.

In children and adults, doctors use it to diagnose and monitor liver and bile duct diseases. These include cirrhosis, hepatitis, and gallstones.

It’ll also help determine if you have sickle cell disease or other conditions that cause hemolytic anemia. That’s a disorder where red blood cells are destroyed faster than they’re made.

High levels of bilirubin can cause a yellowing of your skin and eyes, a condition doctors call jaundice.

High bilirubin levels are common in newborns. Doctors use the age of the newborn and the bilirubin type and levels to determine if treatment is necessary.

A nurse or lab technician will draw blood through a small needle inserted into a vein in your arm. The blood is collected in a tube.

With newborns, blood is usually drawn by using a needle to break the skin of the heel.

Your doctor will send the blood to a lab for analysis.

Before the test, tell your doctor about how active you’ve been and what food and medicines you’ve taken. Certain medications may alter your results.

After the test, you’ll be able to continue with your normal activities right away.

Your doctor may order a bilirubin test if you:

  • Show signs of jaundice
  • Have anemia, or low red blood cells
  • Might be having a toxic reaction to drugs
  • Have a history of heavy drinking
  • Have been exposed to hepatitis viruses
  • Have cirrhosis

You might also have your bilirubin tested if you have symptoms like:

  • Dark urine
  • Nausea and vomiting
  • Abdominal pain or abdominal swelling
  • Clay-colored stools
  • Fatigue

A bilirubin test measures total bilirubin. It can also give levels of two different types of bilirubin: unconjugated and conjugated.

Unconjugated (“indirect”) bilirubin. This is the bilirubin created from red blood cell breakdown. It travels in the blood to the liver.

Conjugated (“direct”) bilirubin. This is the bilirubin once it reaches the liver and undergoes a chemical change. It moves to the intestines before being removed through your stool.

For adults over 18, normal total bilirubin can be up to 1.2 milligrams per deciliter (mg/dl) of blood. For those under 18, the normal level will be will be 1 mg/dl. Normal results for conjugated (direct) bilirubin should be less than 0.3 mg/dl.

Men tend to have slightly higher bilirubin levels than women. African-Americans tend to have lower bilirubin levels than people of other races.

High total bilirubin may be caused by:

  • Anemia
  • Cirrhosis
  • A reaction to a blood transfusion
  • Gilbert syndrome — a common, inherited condition in which there is a deficiency of an enzyme that helps to break down bilirubin.
  • Viral hepatitis
  • A reaction to drugs
  • Alcoholic liver disease
  • Gallstones

Very strenuous exercise, such as marathon running, can increase your bilirubin levels.

Caffeine, penicillin, barbiturates, and nonsteroidal anti-inflammatory drugs (NSAIDs) called salicylates all lower your bilirubin levels.

Lower-than-normal levels of bilirubin aren’t a problem.

In newborns, high bilirubin levels that don’t level out in a few days to 2 weeks may be a sign of:

  • Blood type incompatibility between mother and child
  • Lack of oxygen
  • An inherited infection
  • A disease affecting the liver

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Alkaline Phosphatase Test (ALP): High vs. Low Levels

Written by WebMD Editorial Contributors

  • Why Would I Get This Test?
  • How Is the Test Done?
  • How Do I Prepare?
  • What Do My Results Mean?

Alkaline phosphatase is one kind of enzyme found in your body. Enzymes are proteins that help chemical reactions happen. For instance, they can break big molecules down into smaller parts, or they can help smaller molecules join together to form bigger structures.

You have alkaline phosphatase throughout your body, including your liver, digestive system, kidneys, and bones.

If you show signs of liver disease or a bone disorder, your doctor may order an alkaline phosphatase (ALP) test to measure the amount of the enzyme in your blood and help in diagnosing the problem. Sometimes it’s part of a broader group of tests called a routine liver or hepatic panel, which checks how your liver is working.

If your liver isn’t working right, the amount of ALP in your blood may be high. Doctors often use the test to look for blocked bile ducts. Other conditions that can cause problems with your liver include:

  • Liver cancer
  • Cirrhosis
  • Hepatitis
  • Blockage in the bile ducts

The test can also spot problems with your bones, including:

  • Cancers that have spread to your bones
  • Paget’s disease, which affects how bones grow
  • Issues caused by vitamin D deficiency

The lab will need a small amount of blood to perform the test.

The person in charge of taking your blood will start by placing a tight elastic band, called a tourniquet, around your upper arm. This makes your veins swell with blood.

The lab tech will clean an area of your skin with a germ-killing solution. (It might be a spot inside your elbow or the back of your hand). You’ll feel a small stick when the needle goes into your vein. The blood flows into a small vial attached to the needle.

When the test is done, the lab tech will take the tourniquet off, and you’ll get a bandage on the spot where the needle went in. It takes only a few minutes.

Taking blood samples is usually very safe. Some things that might happen after the test include a bruise at the spot where the needle went in, and a little dizziness. There’s also a slight chance of infection.

You may have to limit food and liquids for several hours before the test. Some medicines interfere with the results, so make sure your doctor knows about all drugs you take, including over-the-counter medicines, vitamins, and supplements.

Be sure to let your doctor know if you are pregnant, because that will increase the level of ALP in your blood.

It generally takes 1-2 days for results to come back from the lab.

Higher-than-normal ALP levels for your age and sex may not necessarily mean you have a problem. (Children and teens naturally have higher levels than adults because their bones are still developing).

If your ALP level is high, your doctor may have you take another test, called an ALP isoenzyme test, to determine whether the alkaline phosphatase in your blood is coming from your liver or your bones.

Low levels of ALP indicate a deficiency in zinc and magnesium but can also be an indicator of a rare genetic disease called hypophosphatasia (HPP), which affects bones and teeth.

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ALT (ALT, Alanine aminotransferase, alanine transaminase, SGPT, Alanine aminotransferase)

Alanine aminotransferase (AlAT, ALT) is an intracellular enzyme, the content of which in the blood of healthy people is low. It is mainly found in the cells of the liver, myocardium, skeletal muscles, pancreas. When cells containing ALT are damaged or destroyed, the enzyme is released into the bloodstream, and its concentration in the blood increases.

Determination of the level of alanine aminotransferase is carried out for the diagnosis of liver diseases and dynamic monitoring of their treatment. The analysis is performed for suspected acute or chronic hepatitis of viral or toxic etiology, cirrhosis of the liver, primary tumors, or metastatic liver disease.

The growth of alanine aminotransferase in the blood in hepatitis is noted much earlier than the onset of the icteric stage, which makes it possible to identify the pathology at the initial stage.

As part of a screening examination (preventive examination of persons who do not have complaints) to assess the state of the liver, before planned hospitalization and surgical treatment, an analysis for ALT is prescribed together with another enzyme – AsAT (aspartate aminotransferase).

The level of ALT together with other enzymes is evaluated in diseases of the pancreas and gallbladder – pancreatitis, cholecystitis, cholelithiasis; if there are complaints of unexplained general weakness, fatigue, yellowness of the skin and sclera, abdominal pain, including a feeling of heaviness in the right hypochondrium, nausea, vomiting.

In addition, the ALT level is taken into account in myocardial infarction and myocarditis, although in cases of heart damage it is only of secondary importance. The study is prescribed for suspected myositis, myodystrophy, when complaints of muscle pain cannot be explained by injuries or excessive physical activity.

Donation is a mandatory reason for testing for ALT.

ALT values ​​are assessed in any chronic disease, before prescribing drug therapy, for example, antitumor, anti-tuberculosis drugs, to assess the initial state of the liver and over time to assess drug tolerance.

Preparation for procedure

It is better to take the test in the morning on an empty stomach (after an 8-14 hour break after the last meal).

Drinking water is allowed.

If necessary, it is permissible to donate blood 4-6 hours after a light meal.

On the eve it is desirable to avoid physical and emotional overload, overeating.

Avoid drinking alcohol 5-6 days before the test.

Avoid smoking 30 minutes before blood sampling.


The survey is completed within one business day.

What can affect the results

Intense physical activity the day before and even a few days before the test can lead to damage to muscle tissue (the so-called tear of muscle fibers) and, accordingly, an increase in the level of ALT. For the same reason, the analysis given after the injury is not informative.

Taking alcohol, certain drugs (antibiotics, non-steroidal anti-inflammatory drugs, anticancer drugs, oral contraceptives, etc.) often distort the result of the study. The list of medications taken should be discussed with the doctor who ordered the analysis, cancel those that are possible – without risk to health.

ALT (ALT, Alanine aminotransferase, alanine transaminase)

For research, blood is taken from a vein. Usually, ASAT (AST, Aspartate aminotransferase) is determined simultaneously and the ratio of ASAT / AlAT (de Ritis coefficient) is estimated.

You can take a blood test for ALT (ALT, Alanine aminotransferase, alanine transaminase) at the nearest INVITRO medical office. The list of offices where biomaterial is accepted for laboratory testing is presented in the “Addresses” section.

Interpretation of test results contains information for the attending physician and is not a diagnosis. The information in this section should not be used for self-diagnosis or self-treatment. An accurate diagnosis is made by the doctor, using both the results of this examination and the necessary information from other sources: history, results of other examinations, etc.


Units of measure: U/l.

Reference values ​​

Floor Age AlAT level, U/l
Both < 5 days < 49
5 days – 6 months < 56
6 – 12 months < 54
1 – 3 years < 33
3 years – 6 years < 29
6 – 12 years old < 39
Male 12 – 17 years old < 27
> 17 years old < 41
Female 12 – 17 years old < 24
> 17 years old < 31

Explanation of indicators

The level of ALT depends on the age and sex of the patient. Minor deviations from the norm, as a rule, do not require drug therapy, and the recommendations associated with them, such as rational nutrition, avoidance of alcohol, etc. should be discussed with your doctor.

The AST/ALAT ratio (de Ritis ratio) is normally between 0.91 and 1.75.

What do low readings mean

A significant decrease in the level of ALT can be detected in severe liver damage, for example, in the terminal stage of liver cirrhosis, when the number of liver cells is significantly reduced.

What do increased indicators mean

First of all, with an increase in ALT, liver problems should be suspected: fatty hepatosis, hepatitis of viral or toxic etiology, cirrhosis of the liver, liver cancer – primary or metastatic.

The degree of increase in ALT is usually associated with the extent or severity of liver damage, but cannot be considered as a determining factor for the prognosis of the disease. The maximum levels of ALT (and AST) – more than a hundred times higher than the norm, are observed in patients with acute viral and drug-induced hepatitis.

A significant increase in alanine aminotransferase can be observed in acute cholecystitis, cholelithiasis, and acute destructive pancreatitis. Another reason may be the use of hepatotoxic drugs that damage liver cells.

An increase in the level of ALT is detected with extensive injuries of the skeletal muscles, severe myositis and myodystrophy, frequent intramuscular injections.

A less significant increase in ALT is recorded in acute myocardial infarction and myocarditis.

Additional examination in case of deviation of the indicator from the norm

If a change (often an increase) in the level of ALT is detected, patients are consulted

general practitioners



, hepatologists, infectious disease specialists.

To clarify the diagnosis, in addition to ALT, other liver enzymes (AST, gamma-HT, alkaline phosphatase, bilirubin), clinical blood counts, and markers of viral hepatitis, primarily hepatitis B and hepatitis C, are usually examined.

An ultrasound examination of the abdominal organs is performed, according to indications – computed tomography (CT) with contrast.

If damage to the skeletal muscles is suspected, the CPK enzyme is additionally examined and a rheumatologist is consulted.

If a heart muscle disorder is suspected, a cardiologist should be consulted. Usually the doctor prescribes additional electrocardiography (ECG), echocardiography, blood test for CF-CF, troponin I.

O.P. The role of new reference values ​​of alanine aminotransferase in the diagnosis of various forms of non-alcoholic fatty liver disease in patients with metabolic syndrome. Journal of Biomedical Technologies № 1. 2015. P. 9-15.

  • Clinical guidelines “Cirrhosis and fibrosis of the liver.” Developed by: Russian Society for the Study of the Liver, Russian Gastroenterological Association. – 2021.
  • Clinical guidelines “Liver cancer (hepatocellular)”. Developed by: Association of Oncologists of Russia, Russian Society of Clinical Oncology, Russian Society of Radiologists and Radiologists. – 2020.

    The information in this section should not be used for self-diagnosis or self-treatment. In case of pain or other exacerbation of the disease, only the attending physician should prescribe diagnostic tests. For diagnosis and proper treatment, you should contact your doctor.
    For a correct assessment of the results of your analyzes in dynamics, it is preferable to do studies in the same laboratory, since different laboratories may use different research methods and units of measurement to perform the same analyzes.

    The norm of ALT and AST in the blood test in women: what you need to know


    • 1 The norm of ALT and AST in the blood of women: what indicators are the norm and what do the deviations say?
      • 1.1 Blood test norm for women: ALT and AST
      • 1.2 What is a blood test?
      • 1.3 What do ALT and AST mean?
      • 1.4 Why is it important to know the ALT and AST levels?
      • 1. 5 How is ALT and AST analyzed?
      • 1.6 How do I prepare for an ALT and AST test?
      • 1.7 The norm of ALT and AST in women: age characteristics
      • 1.8 What diseases can affect the level of ALT and AST in the blood of women?
      • 1.9 What should I do if my ALT and AST levels are elevated?
      • 1.10 What factors can increase blood levels of ALT and AST?
      • 1.11 Can I decode the results of ALT and AST analysis myself?
      • 1.12 Related videos:
      • 1.13 Q&A:
          • What are ALT and AST in a blood test?
          • What causes an increase in ALT and AST levels?
          • What are the norms for ALT and AST in women?
          • Can elevated levels of ALT and AST in women be associated with medication?
          • Can elevated levels of ALT and AST in women indicate cancer?
          • What should be done if the level of ALT and AST in the blood of a woman is elevated?

    Find out what the norm of alt and ast means in a blood test for women. Which values ​​are normal, and which may indicate diseases. The importance of timely and correct decoding of a blood test for maintaining health.

    The results of a biochemical blood test are one of the key indicators of the health of the body. It is especially important to correctly interpret the level of AST (aspartate aminotransferase) and ALT (alanine aminotransferase), as they are a reflection of the work of the liver. Blood tests for AST and ALT are often prescribed in combination with other indicators to assess liver function, determine the nature of the disease and monitor the progress of treatment.

    For women, normal levels of AST and ALT may differ slightly from those for men, in addition, during pregnancy and some other conditions, there may be significant changes in enzyme levels. Therefore, it is important to know the features of the interpretation of the results and the possible causes of deviations from the norm.

    In this article we will tell you what are the norms of AST and ALT levels in the blood in women, what means their increase or decrease, as well as what factors can affect the result of the tests. If you find deviations from the norm, do not panic, perhaps this is a temporary phenomenon, but additional consultation with a doctor and diagnosis of the condition of the liver is necessary.

    Blood test norm for women: ALT and AST

    ALT (alanine aminotransferase) and AST (aspartate aminotransferase) are enzymes that are found in the cells of the liver, heart, muscles and other tissues of the body. Their level in the blood can be increased in diseases of these organs, as well as in other pathologies.

    The norm of AST in women is from 7 to 31 units per liter of blood. An increase in AST levels can be associated with diseases of the liver, cardiovascular system, as well as muscle injuries.

    It is important to remember that ALT and AST levels may differ depending on the laboratory where the blood was tested. Therefore, the doctor should interpret the results, taking into account all the factors affecting the level of these enzymes.

    What is a blood test?

    A blood test is a laboratory study of the biological fluid that circulates through a person’s blood vessels. This analysis is one of the most common methods for diagnosing many diseases, as well as monitoring the state of the body, both in case of deterioration and improvement of its health.

    A blood test goes through many stages, from taking blood to interpreting the results. When conducting an analysis, various factors should be taken into account, such as age, gender, physical condition, the presence of chronic diseases and the use of drugs.

    Various blood tests, such as hemoglobin, leukocytes, platelets, ALT, AST and many others, may indicate various diseases or abnormalities in the body.

    What do ALT and AST mean?

    ALT and AST are enzymes found in liver cells. ALT (alanine aminotransferase) and AST (aspartate aminotransferase) can be used as indicators of liver damage. These enzymes are released from liver cells into the bloodstream when an organ is damaged or diseased, and their levels can indicate how severe the damage is.

    High levels of ALT and AST in women’s blood may indicate the presence of liver disease or other diseases such as hepatitis, cirrhosis, or liver tumors. However, elevated levels of ALT and AST may also be indicative of other non-liver related conditions, such as heart failure.

    Why is it important to know the norms of ALT and AST?

    Alanine aminotransferase (ALT) and Aspartate aminotransferase (AST) are enzymes found in liver and heart cells. If their level in the blood is elevated, this may indicate damage to the cells of these organs.

    Measurement of ALT and AST blood levels is an important blood test that provides information about the condition of the liver and heart in women. Elevated levels of ALT and AST may indicate various diseases, such as hepatitis, cirrhosis, heart failure, and others.

    ALT and AST values ​​are indicative and may vary depending on the woman’s age, sex and lifestyle. Therefore, it is important to know the norm of ALT and AST for women in order to make it easier to determine the presence of any diseases.

    If ALT and AST are elevated, see a doctor who can diagnose and suggest treatment. Treatment may be aimed at eliminating the causes of increased enzyme levels, as well as restoring liver and heart function.

    How is ALT and AST analyzed?

    The ALT and AST test is a routine blood test. Usually, blood is taken from a vein in the elbow for analysis. Before passing the analysis, you must follow the rules of preparation.

    After the blood has been collected, it is sent to a laboratory where it is analyzed for ALT and AST levels. The results of the analysis are usually ready in a few days.

    When analyzing ALT and AST, be aware that the results may vary depending on age, gender, physical activity and the use of certain medications. Therefore, before the analysis, it is necessary to consult a doctor and follow the recommendations for preparation.

    How do I prepare for an ALT and AST test?

    ALT and AST assays require some preparation in order for the results to be accurate and reliable. Here are some tips to help you properly prepare for this analysis.

    • Refusal of food 8-12 hours before the test. It is best to take the test in the morning on an empty stomach so as not to affect the results. This means that 8-12 hours before blood collection, you need to refuse food.
    • Medication withdrawal. Be sure to tell your doctor if you are taking any medications. Some medicines may interfere with the results of the test. If your doctor thinks you need to stop taking your medication, it’s best to follow their advice.
    • Refusal of alcohol one day before the analysis. Alcohol can interfere with test results, so alcohol should be avoided the day before the test.
    • Maintaining rest and avoiding exercise. Physical activity can also affect the results of the test, so the day before it is taken, physical activity should be avoided and rest should be observed.
    • Blood collection compliance. To obtain accurate and reliable results, you must follow the rules for collecting blood. The blood collection process itself should not take more than 5-7 minutes and take place in a sterile environment.

    By following these guidelines, you can be confident that your ALT and AST results will be reliable and will help your doctor make the right diagnosis and treatment.

    The norm of ALT and AST in women: age characteristics

    ALT and AST are important indicators of the functional state of the liver, determined in the blood.

    It is possible to establish the norm of ALT and AST in the blood of women only taking into account age characteristics.

    So, for example, in women under the age of 50, the ALT norm is up to 31 units per liter of blood, and in women over 50 years old – up to 35 units.

    The norm of AST for women under the age of 50 is up to 31 units per liter of blood, after 50 years – up to 35 units.

    It should also be noted that during pregnancy, women may experience changes in ALT and AST levels, which usually return to normal after childbirth.

    In any case, if you find abnormalities in ALT and AST, you should contact a specialist for further diagnosis and treatment.

    What diseases can affect the blood levels of ALT and AST in women?

    The blood levels of ALT and AST in women can be increased as a result of various diseases. For example, hepatitis is one of the main causes of elevated levels of ALT and AST. This is due to the fact that these enzymes are found in high concentration in the liver, and in hepatitis, the liver tissue can be damaged, which leads to the release of large amounts of ALT and AST into the blood.

    In addition, diseases that affect the biliary tract, such as gallstones and cholangitis, can also increase ALT and AST levels. The levels of these enzymes may also increase in women with cardiovascular disease such as myocardial infarction or arrhythmia.

    1. Hepatitis;
    2. Cirrhosis of the liver;
    3. Oncological diseases;
    4. Muscular diseases;
    5. Cholelithiasis;
    6. Cholangitis;
    7. Cardiovascular disease;

    What if ALT and AST levels are high?

    If ALT and AST levels are elevated in a woman’s blood test, a doctor should be consulted for diagnosis and possible causes. Perhaps an increase in the level of these indicators may indicate diseases of the liver or other organs.

    Your doctor may order additional tests, such as an ultrasound of your liver, a CT scan, or a liver biopsy, to help you diagnose. In addition, it is necessary to analyze urine and blood for the presence of infections, viruses and other pathological processes.

    If the reason for the increase in ALT and AST levels is related to the disease, it is necessary to undergo treatment prescribed by a doctor. This may include medication, diet, and other measures, depending on the specific disease and its stage.

    In addition, women who have elevated ALT and AST levels should lead a healthy lifestyle, give up addictions and watch their diet. It is recommended to increase the amount of vegetables and fruits consumed, reduce the intake of fatty and fried foods, and also pay attention to the quantitative and qualitative composition of food.

    • see a doctor for diagnosis;
    • complete the required tests;
    • get treatment prescribed by your doctor;
    • lead a healthy lifestyle and watch your diet.

    What factors can increase blood levels of ALT and AST?

    Preparations. In addition to drugs that fight liver disease, many drugs can increase blood levels of ALT and AST, such as antiviral drugs, anabolic steroids, anticancer drugs, and others.

    Alcohol. Regular alcohol consumption can lead to liver damage and possible increase in blood levels of ALT and AST.

    Wrong diet. Excessive consumption of fatty and fried foods can lead to impaired liver function and increased levels of ALT and AST in the blood.

    Inflammatory diseases of the liver. Viral, alcoholic or autoimmune hepatitis, cirrhosis of the liver, fatty degeneration cause liver inflammation, which increases the level of ALT and AST in the blood.

    Examples of drugs that can increase ALT and AST in the blood Drug Group

    Aspirin Analgesic
    Antibiotics Antibacterial drugs
    Paraketamol Analgesic
    Ampicillin Antibacterials

    Can I decode ALT and AST test results myself?

    Aspartate aminotransferase (AST) and Alanine aminotransferase (ALT) are enzymes that are located in the liver cells without penetrating into the blood. They are released into the blood only under pathological conditions of the organ. Changes in the levels of these enzymes indicate damage to liver and/or heart cells.

    ALT and AST analysis results may only be decoded by qualified medical personnel after examining the patient and performing other investigations.

    Although regular analysis of ALT and AST levels helps to identify possible diseases in the very early stages, you should not try to diagnose yourself. The best solution is to consult with your doctor.

    Related videos:


    What is ALT and AST in a blood test?

    ALT and AST are enzymes found in the cells of the liver, heart, muscles and other organs. If their blood levels are elevated, this may indicate damage to the cells of these organs.

    What causes ALT and AST levels to rise?

    Elevated levels of ALT and AST in the blood may be associated with diseases of the liver (hepatitis, cirrhosis), cardiovascular system (heart attack, cardiomyopathy), muscles (muscular dystrophy) and other organs. It can also be caused by taking certain medications, alcohol, or toxic substances.

    What are the norms for ALT and AST in women?

    Guideline values ​​for ALT and AST may vary slightly depending on the laboratory and age of the woman. Typically, the ALT level should not exceed 31 U/L, and the AST level should not exceed 30 U/L.

    Can elevated levels of ALT and AST in women be associated with medication?

    Yes, some medicines can increase blood levels of ALT and AST, such as antibiotics, antiparkinsonian drugs, and some antiviral drugs. Therefore, if you are taking any medications, tell your doctor before taking a blood test.

    Can elevated levels of ALT and AST in women indicate cancer?

    No, elevated levels of ALT and AST are not specific to cancer and are not the main sign of cancer.