What is an ALT blood test. How does ALT indicate liver health. When should you get an ALT test. What do ALT results mean. How is ALT testing performed. What other liver function tests are important.

What is ALT and Why is it Important for Liver Health?

Alanine aminotransferase (ALT) is an enzyme primarily found in the liver that plays a crucial role in metabolism. An ALT blood test measures the levels of this enzyme in the bloodstream, serving as an important indicator of liver health and function.

ALT is vital for several reasons:

• It helps break down food into energy
• Elevated levels can signal liver damage or disease
• It assists in monitoring liver function over time
• ALT tests are often part of comprehensive liver panels

The liver performs numerous essential functions in the body, including:

1. Producing bile for digestion
2. Removing toxins from the blood
3. Synthesizing proteins and cholesterol
4. Storing vitamins and minerals
5. Regulating blood sugar levels

Given the liver’s critical role in maintaining overall health, monitoring ALT levels can provide valuable insights into liver function and potential issues.

How does ALT indicate liver health?

Under normal circumstances, ALT levels in the blood are relatively low. However, when liver cells are damaged or die, they release ALT into the bloodstream, causing levels to rise. This increase serves as a warning sign, prompting further investigation into potential liver problems.

When Should You Get an ALT Blood Test?

Healthcare providers may recommend an ALT test for various reasons, including:

• Routine health screenings
• Monitoring known liver conditions
• Evaluating unexplained symptoms
• Assessing medication side effects

Specific symptoms that might warrant an ALT test include:

1. Abdominal pain or swelling
2. Nausea and vomiting
3. Jaundice (yellowing of skin or eyes)
4. Extreme fatigue
5. Dark urine or light-colored stools
6. Persistent itching

Are there risk factors that necessitate regular ALT testing?

Certain individuals may require more frequent ALT testing due to increased risk factors for liver disease. These include:

• History of hepatitis exposure
• Excessive alcohol consumption
• Family history of liver disease
• Use of medications known to affect liver function
• Obesity or metabolic syndrome
• Diabetes

How is an ALT Blood Test Performed?

The ALT blood test is a straightforward procedure that typically involves the following steps:

1. A healthcare professional cleans the injection site, usually on the arm
2. A tourniquet is applied to make the vein more visible
3. A needle is inserted to draw a small amount of blood
4. The blood sample is collected in a vial or tube
5. The needle is removed, and pressure is applied to stop bleeding
6. A bandage is placed over the site

Is any special preparation required for an ALT test?

Generally, no special preparation is needed for an ALT test. However, your healthcare provider may advise:

• Fasting for a few hours before the test
• Disclosing all medications and supplements you’re taking
• Avoiding strenuous exercise 24 hours prior to the test

Understanding ALT Test Results: What Do the Numbers Mean?

ALT test results are typically reported in units per liter (U/L). Normal ranges can vary slightly between laboratories, but generally:

• Normal ALT levels: 7-55 U/L
• Slightly elevated: 55-200 U/L
• Moderately elevated: 200-1000 U/L
• Severely elevated: >1000 U/L

What can cause elevated ALT levels?

Various factors can lead to increased ALT levels, including:

1. Viral hepatitis (A, B, C)
2. Alcoholic liver disease
3. Non-alcoholic fatty liver disease (NAFLD)
4. Cirrhosis
5. Certain medications (e.g., statins, acetaminophen)
6. Autoimmune hepatitis
7. Liver cancer
8. Heart failure
9. Muscle injury or disease

Can ALT levels be too low?

While elevated ALT levels are more commonly associated with liver issues, abnormally low levels can also occur. Potential causes of low ALT include:

• Vitamin B6 deficiency
• Severe kidney disease
• Some medications

However, low ALT levels are generally less concerning than elevated levels in terms of liver health.

Other Important Liver Function Tests

While ALT is a crucial marker of liver health, it’s often part of a broader panel of liver function tests. Other important tests include:

1. Aspartate aminotransferase (AST)
2. Alkaline phosphatase (ALP)
3. Gamma-glutamyl transferase (GGT)
4. Bilirubin
5. Albumin
6. Prothrombin time (PT)

How do these tests complement ALT results?

Each of these tests provides unique insights into liver function:

• AST: Often elevated alongside ALT in liver damage
• ALP: Can indicate bile duct obstruction or bone disorders
• GGT: Sensitive to alcohol use and certain medications
• Bilirubin: Elevated in conditions like jaundice
• Albumin: Reflects liver’s protein production capacity
• PT: Measures blood clotting function, which can be impaired in liver disease

The Importance of the AST/ALT Ratio

The ratio of AST to ALT can provide valuable information about the nature and severity of liver damage. This ratio is particularly useful in distinguishing between different types of liver diseases.

What does the AST/ALT ratio indicate?

• AST/ALT ratio < 1: Typically seen in viral hepatitis and non-alcoholic fatty liver disease
• AST/ALT ratio > 2: Often indicates alcoholic liver disease
• AST/ALT ratio between 1-2: Can be seen in various liver conditions and requires further investigation

It’s important to note that the AST/ALT ratio should always be interpreted in conjunction with other clinical findings and test results.

Lifestyle Changes to Improve Liver Health and ALT Levels

If you’ve received elevated ALT results or are concerned about your liver health, several lifestyle modifications can help:

1. Limit alcohol consumption
2. Maintain a healthy weight
3. Exercise regularly
4. Eat a balanced, liver-friendly diet
5. Avoid unnecessary medications
6. Get vaccinated against hepatitis A and B
7. Manage underlying conditions like diabetes and high cholesterol

What foods are beneficial for liver health?

A liver-friendly diet typically includes:

• Fruits and vegetables high in antioxidants
• Whole grains
• Lean proteins
• Healthy fats (e.g., olive oil, avocados)
• Green tea
• Coffee (in moderation)

Conversely, it’s advisable to limit intake of processed foods, saturated fats, and added sugars.

When to Seek Medical Attention for Abnormal ALT Results

While mildly elevated ALT levels may not always indicate a serious problem, it’s important to follow up with your healthcare provider if:

• Your ALT levels are consistently elevated
• You experience symptoms of liver disease
• You have risk factors for liver problems
• Your ALT levels are severely elevated (>1000 U/L)

What additional tests might be recommended?

Depending on your ALT results and overall clinical picture, your doctor may recommend:

1. Comprehensive metabolic panel
2. Hepatitis serologies
3. Autoimmune markers
4. Imaging studies (ultrasound, CT, or MRI)
5. Liver biopsy (in some cases)

These additional tests can help pinpoint the underlying cause of elevated ALT levels and guide appropriate treatment strategies.

The Future of Liver Function Testing: Emerging Technologies and Biomarkers

While ALT remains a cornerstone of liver function testing, research is ongoing to develop more sensitive and specific markers of liver health. Some promising areas include:

• Non-invasive imaging techniques (e.g., elastography)
• Novel blood-based biomarkers
• Genetic testing for liver disease susceptibility
• Artificial intelligence-assisted interpretation of liver function tests

How might these advancements improve liver disease diagnosis and management?

Emerging technologies and biomarkers have the potential to:

1. Detect liver damage at earlier stages
2. Provide more accurate prognostic information
3. Guide personalized treatment approaches
4. Reduce the need for invasive procedures like liver biopsies
5. Improve monitoring of treatment effectiveness

As research progresses, these advancements may complement or even replace traditional liver function tests like ALT in certain clinical scenarios.

Alanine Aminotransferase (ALT) Test and Results (aka SGPT Test)

Written by WebMD Editorial Contributors

Medically Reviewed by Jennifer Robinson, MD on May 20, 2021

• Why Is ALT Important?
• Why Would My Doctor Order This Test?
• How Do I Prepare?
• What Happens During the Test?
• What Are the Risks?
• What Do the Results Mean?
• What Other Tests Will I Take?
• More

The alanine aminotransferase (ALT) test is a blood test that checks for liver damage. Your doctor can use this test to find out if a disease, drug, or injury has damaged your liver.

Your liver does a lot of important things for you:

• It makes a fluid called bile that helps your body digest food.
• It removes waste products and other toxins from your blood.
• It produces proteins and cholesterol.

Diseases such as hepatitis and cirrhosis can damage your liver and prevent it from doing its many jobs.

This enzyme is found mainly in your liver. Smaller amounts of ALT are in your kidneys and other organs, too.

Your body uses ALT to break down food into energy. Normally, ALT levels in the blood are low. If your liver is damaged, it will release more ALT into your blood and levels will rise. (ALT used to be called serum glutamic-pyruvic transaminase, or SGPT).

Doctors often give the ALT test along with other liver tests.

Your doctor might recommend ALT if you have symptoms of liver disease or damage, such as:

• Stomach pain or swelling
• Nausea
• Vomiting
• Yellow skin or eyes (a condition called jaundice)
• Weakness
• Extreme tiredness (fatigue)
• Dark-colored urine
• Light-colored poop
• Itchy skin

Here are some reasons you might get this test:

• You’ve been exposed to the hepatitis virus.
• You drink a lot of alcohol.
• You have a family history of liver disease.
• You take medicine that’s known to cause liver damage.

The ALT test can be done as part of a blood panel during a regular exam. If you’ve already been diagnosed with liver disease, your doctor can use the ALT test to see how well your treatment is working.

You don’t need any special preparation for the ALT test. Your doctor might ask you to stop eating or drinking a few hours before the test.

Tell your doctor what prescription drugs or supplements you take. Some medicines can affect the results of this test.

A nurse or lab tech will take a sample of your blood, usually from a vein in your arm. They will first tie a band around the upper part of your arm to make your vein fill with blood and swell up. Then they will clean the area with an antiseptic and place a needle into your vein. Your blood will collect into a vial or tube.

The blood test should take only a couple of minutes. After your blood is taken, the lab tech will remove the needle and band, then put a piece of gauze and a bandage over the spot the needle went in to stop the bleeding.

The ALT blood test is safe. Risks are usually minor, and can include:

• Bleeding
• Bruising
• Infection
• Slight pain when the needle is inserted
• Fainting or feeling dizzy

You should get your results in about a day. A normal ALT test result can range from 7 to 55 units per liter (U/L). Levels are normally higher in men.

Slightly high ALT levels may be caused by:

• Alcohol abuse
• Cirrhosis (long-term damage and scarring of the liver)
• Mononucleosis
• Drugs such as statins, aspirin, and some sleep aids

Moderately high ALT levels may be because of:

• Chronic (ongoing) liver disease
• Alcohol abuse
• Cirrhosis
• Blockage of the bile ducts
• Heart attack or heart failure (when your heart can’t pump enough blood to your body)
• Kidney damage
• Muscle injury
• Damage to red blood cells
• Heat stroke
• Too much vitamin A

Very high ALT levels can be caused by:

• Acute viral hepatitis
• An overdose of drugs such as acetaminophen (Tylenol)
• Liver cancer
• Sepsis

ALT usually is done as part of a group of liver function tests called a liver panel.

This panel also includes an aspartate aminotransferase (AST) test. AST is another liver enzyme. As with ALT, the levels of AST in your blood rise if your liver is damaged.

Comparing ALT with AST levels gives your doctor more information about the health of your liver. The ALT-to-AST ratio can help your doctor figure out how severe the liver damage is and what might have caused it.

To find out what type of liver disease you have, your doctor might also test the levels of other enzymes and proteins found in your liver, including:

• Albumin
• Alkaline phosphatase
• Bilirubin
• Lactate dehydrogenase (LDH)
• Total protein

Talk to your doctor to make sure you understand all of your liver test results. Also find out how these results might affect your treatment.

Top Picks

Alanine Aminotransferase (ALT) Test and Results (aka SGPT Test)

Written by WebMD Editorial Contributors

Medically Reviewed by Jennifer Robinson, MD on May 20, 2021

• Why Is ALT Important?
• Why Would My Doctor Order This Test?
• How Do I Prepare?
• What Happens During the Test?
• What Are the Risks?
• What Do the Results Mean?
• What Other Tests Will I Take?
• More

The alanine aminotransferase (ALT) test is a blood test that checks for liver damage. Your doctor can use this test to find out if a disease, drug, or injury has damaged your liver.

Your liver does a lot of important things for you:

• It makes a fluid called bile that helps your body digest food.
• It removes waste products and other toxins from your blood.
• It produces proteins and cholesterol.

Diseases such as hepatitis and cirrhosis can damage your liver and prevent it from doing its many jobs.

This enzyme is found mainly in your liver. Smaller amounts of ALT are in your kidneys and other organs, too.

Your body uses ALT to break down food into energy. Normally, ALT levels in the blood are low. If your liver is damaged, it will release more ALT into your blood and levels will rise. (ALT used to be called serum glutamic-pyruvic transaminase, or SGPT).

Doctors often give the ALT test along with other liver tests.

Your doctor might recommend ALT if you have symptoms of liver disease or damage, such as:

• Stomach pain or swelling
• Nausea
• Vomiting
• Yellow skin or eyes (a condition called jaundice)
• Weakness
• Extreme tiredness (fatigue)
• Dark-colored urine
• Light-colored poop
• Itchy skin

Here are some reasons you might get this test:

• You’ve been exposed to the hepatitis virus.
• You drink a lot of alcohol.
• You have a family history of liver disease.
• You take medicine that’s known to cause liver damage.

The ALT test can be done as part of a blood panel during a regular exam. If you’ve already been diagnosed with liver disease, your doctor can use the ALT test to see how well your treatment is working.

You don’t need any special preparation for the ALT test. Your doctor might ask you to stop eating or drinking a few hours before the test.

Tell your doctor what prescription drugs or supplements you take. Some medicines can affect the results of this test.

A nurse or lab tech will take a sample of your blood, usually from a vein in your arm. They will first tie a band around the upper part of your arm to make your vein fill with blood and swell up. Then they will clean the area with an antiseptic and place a needle into your vein. Your blood will collect into a vial or tube.

The blood test should take only a couple of minutes. After your blood is taken, the lab tech will remove the needle and band, then put a piece of gauze and a bandage over the spot the needle went in to stop the bleeding.

The ALT blood test is safe. Risks are usually minor, and can include:

• Bleeding
• Bruising
• Infection
• Slight pain when the needle is inserted
• Fainting or feeling dizzy

You should get your results in about a day. A normal ALT test result can range from 7 to 55 units per liter (U/L). Levels are normally higher in men.

Slightly high ALT levels may be caused by:

• Alcohol abuse
• Cirrhosis (long-term damage and scarring of the liver)
• Mononucleosis
• Drugs such as statins, aspirin, and some sleep aids

Moderately high ALT levels may be because of:

• Chronic (ongoing) liver disease
• Alcohol abuse
• Cirrhosis
• Blockage of the bile ducts
• Heart attack or heart failure (when your heart can’t pump enough blood to your body)
• Kidney damage
• Muscle injury
• Damage to red blood cells
• Heat stroke
• Too much vitamin A

Very high ALT levels can be caused by:

• Acute viral hepatitis
• An overdose of drugs such as acetaminophen (Tylenol)
• Liver cancer
• Sepsis

ALT usually is done as part of a group of liver function tests called a liver panel.

This panel also includes an aspartate aminotransferase (AST) test. AST is another liver enzyme. As with ALT, the levels of AST in your blood rise if your liver is damaged.

Comparing ALT with AST levels gives your doctor more information about the health of your liver. The ALT-to-AST ratio can help your doctor figure out how severe the liver damage is and what might have caused it.

To find out what type of liver disease you have, your doctor might also test the levels of other enzymes and proteins found in your liver, including:

• Albumin
• Alkaline phosphatase
• Bilirubin
• Lactate dehydrogenase (LDH)
• Total protein

Talk to your doctor to make sure you understand all of your liver test results. Also find out how these results might affect your treatment.

Top Picks

ALT (AlAT, alanine aminotransferase)

ALT is an enzyme from the group of aminotransferases that is responsible for amino acid metabolism and is produced intracellularly. Normally, the content of ALT in the blood is negligible, and the highest level of the enzyme is observed in the liver cells. Therefore, with an increase in the concentration of ALT in the blood, the first suspicion falls on asymptomatic lesions of this particular organ. As a rule, this analysis is necessary after a long-term use of medications, interaction with toxic substances (including alcohol), in the diagnosis of hepatitis, and suspicion of pancreatitis.

An increase in ALT in the blood in a certain proportion with another enzyme, AST (aspartate aminotransferase), may also indicate a past heart attack.

Test results are highly affected by food intake, so it is important to strictly abstain during the 12 hours prior to blood sampling.

ALT (alanine aminotransferase, ALAT) is an intracellular enzyme from the group of transferases, a subgroup of transaminases, which catalyzes the conversion of a-keto acids into amino acids by transferring amino groups. Normally, only a small part of this enzyme disappears into the blood. The enzyme is present mainly in the cytoplasm of hepatocytes, but it is also found in skeletal muscle and myocardial cells. The biochemical activity of ALT in the liver is almost 10 times higher than in the myocardium and skeletal muscles, therefore, an increase in the level of ALT in the blood is mainly considered as an indicator of damage to the liver parenchyma. When liver cells are damaged, the integrity of their membrane is violated and ALT enters the bloodstream. ALT has a greater diagnostic sensitivity in diseases of the hepatobiliary system than AST.

If ALT (ALAT) biochemical blood test showed an increase in ALT activity by 50 times or more, then this can mainly be due to acute violation of hepatic perfusion, acute necrosis of liver cells caused by exotoxins, including paracetamol and carbon tetrachloride, viral hepatitis , infectious mononucleosis. An increase in the concentration of ALT in the blood is diagnostically significant, since its level increases even before the appearance of other clinical symptoms of liver diseases (jaundice, etc. ). With viral hepatitis, an increase in enzyme activity occurs at a very early time – in the prodromal period (it is noted in 50% of patients – in 5 days, in 90% – 2 days before the clinical manifestation of the disease). High values ​​of ALT and AST are also observed in toxic hepatitis, especially in severe cases. A moderate increase in transaminases is observed with alcoholic liver damage. Depending on the stage of the cirrhotic process, the levels of ALT and AST can be either at the upper limit of normal, or at a 4-5-fold increase from the upper limit (the level of AST is higher than ALT). In patients with primary or metastatic liver carcinomas, an increase in transaminase activity by 5-10 times is observed, however, there are cases when their level remains within the normal range, mainly in the early stages of malignant infiltration of the organ. The level in the blood test ALT (ALAT), exceeding more than 15 times the upper limit of normal, is always an indicator of acute hepatocellular necrosis of toxic, viral or circulatory origin.

An increase in the level in the analysis of ALT is also observed in myocardial infarction, since this enzyme is also found in the heart muscle, however, its increase compared to AST is insignificant, since the activity of ALT in cardiomyocytes, unlike AST, is low. In uncomplicated myocardial infarctions, blood levels of ALT (ALAT) remain within the normal range or their slight increase is observed. An increase in serum ALT concentration in myocardial infarction may indicate the development of congestion in the liver.

Indications for

• Diagnosis of liver diseases.
• Examination of contact persons in the focus of viral hepatitis.
• Monitoring of patients with hepatitis of various etiologies.
• Donor screening.

Preparation for analysis

• It is recommended to donate blood for research on an empty stomach, you can only drink water.
• At least 8 hours must have elapsed since the last meal.
• Blood sampling should be done before starting medications (if possible) or no earlier than 1-2 weeks after they are discontinued. If it is impossible to cancel drugs in the direction for the study, it should be indicated which drugs the patient receives and in what doses.
• The day before blood sampling, limit fatty and fried foods, do not take alcohol, exclude heavy physical exertion.
• It is not recommended to donate blood for research immediately after radiography, fluorography, ultrasound – research, rectal examination or physiotherapy procedures.

Factors influencing the results of the analysis

• Hemolysis, chylosis tests, alcohol intake, treatment with hepatotoxic drugs (psychotropic drugs, anabolic steroids, contraceptives, salicylates, sulfonamides, antibiotics, immunosuppressants, anticancer drugs, drugs for chemotherapy and anesthesia).

Prescribing physician

General practitioner, surgeon, infectious disease specialist, endocrinologist, hematologist, internist, gastroenterologist.

Attention! The interpretation of test results is for informational purposes, is not a diagnosis and does not replace the advice of a doctor. Reference values ​​may differ from those indicated depending on the equipment used, actual values ​​will be indicated on the results sheet.

– Unit: U/L

– Increase:

• Necrosis of liver cells of any etiology (viral hepatitis, toxic liver damage).
• Cirrhosis of the liver.
• Cholestatic and obstructive jaundice.
• Myocarditis.
• Heart failure.
• Myocardial infarction.
• Myositis.
• Major trauma and necrosis of skeletal muscle.
• Pancreatitis.
• Burn disease.
• Alcoholism.
• Liver cancer (primary and metastatic).

– Decrease:

• Not diagnostic.

Alanine aminotransferase (ALT) blood test

Alanine aminotransferase in the blood – a liver enzyme involved in the metabolism of amino acids, is found in large quantities in the liver, kidneys, heart muscle, skeletal muscles.

Read reviews about ALT analysis ►

What does the ALT level indicate?

An increase in ALT indicates the occurrence of inflammatory processes in the body. They can be caused by the following diseases:

• hepatitis;

• liver cancer;

• pancreatitis;

• myocarditis;

• cirrhosis;

• Myocardial infarction.

Decrease in the level of ALT is observed in severe liver diseases: necrosis, cirrhosis (with a decrease in the number of cells synthesizing ALT). The result of a blood test will show a low content of alanine aminotransferase in vitamin B6 deficiency.

When the cells of the liver, kidneys, heart muscle, skeletal muscles are destroyed, caused by various pathological processes, ALT is released into the human blood – the analysis will show an increased level of the enzyme in the blood.