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What is alt in blood test normal range: 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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Types of Liver Problems & Their Causes

Written by Steven Brown

  • Infections
  • Immune System Problems
  • Cancer and Tumors
  • Conditions You Inherit
  • Other Causes of Liver Disease

Your liver does a lot of things that keep you healthy. It turns nutrients into chemicals your body needs. It filters out poisons. It helps turn food into energy. So when your liver doesn’t work well, that can affect your whole body.

Different things can cause serious liver conditions. You’ll want to know about the top causes.

Sometimes, the problem is that you have an infection that inflames your liver. Viral hepatitis is the most common cause, including:

  • Hepatitis A. Most people get it by eating or drinking something that’s tainted by fecal matter. You might not have any symptoms. It usually goes away by itself within 6 months without any long-term harm.
  • Hepatitis B. You get it from somebody else, such as through unprotected sex or taking drugs with shared needles. If it lasts longer than 6 months, it makes you more likely to get liver cancer or other diseases.
  • Hepatitis C comes from infected blood that gets into your blood. You might get it if you take drugs with shared needles or in connection with HIV. If you’re a health-care worker, you might get it from an infected needle that accidentally sticks you. Symptoms may not show up for many years. For reasons that aren’t quite clear, baby boomers are at risk for hepatitis C and should be tested for it.

Your immune system fights off invaders including bacteria and viruses. But it might go wrong and attack one or more parts of your body, such as your liver.

  • Autoimmune hepatitis inflames your liver. It can lead to other disorders and even liver failure. It strikes girls and women more often than boys or men.
  • Primary biliary cholangitis attacks tiny tubes in your liver called bile ducts. They carry bile, a chemical that helps you digest food. When the ducts are injured, the bile backs up inside your liver and scars it. Women come down with this more often than men.
  • Primary sclerosing cholangitis scars your bile ducts, and it can eventually block them. The bile builds up inside your liver, and that makes it harder for your liver to work. It may lead to liver cancer, and you might someday need a liver transplant. Men are more likely than women to get it.

If cancer shows up in your liver, that’s most likely because it has spread from another part of your body, like your lungs, colon, or breasts. But a few cancers can start in the liver.

  • Liver cancer affects women more often than men, and African-Americans more often than whites. Your doctor might call it hepatocellular carcinoma. It’s more likely if you have hepatitis or drink too much.
  • Bile duct cancer strikes the tubes that run from your liver to your small intestine to carry bile, a fluid that helps you digest food. This kind of cancer mainly affects people over age 50, but it’s uncommon.
  • Liver cell adenoma is a tumor that doesn’t have cancer. It’s uncommon, but women who take birth control pills for a long time are more prone than other people to develop it. There’s a small chance the tumor could eventually turn into cancer.

Some inherited liver disorders only happen if they run in your family.

  • Hemochromatosis makes your body store up too much of the iron from your food. The extra iron builds up in your liver, heart, or other organs. It can lead to life-threatening conditions such as liver diseases, heart disease, or diabetes.
  • Hyperoxaluria hits when your urine has too much of a chemical called oxalate. In this condition, your liver makes too much oxalate due to a genetic mutation. This can cause kidney stones and kidney failure. If your kidneys do fail, that can give you oxalosis, where the oxalate collects in other organs and causes more trouble.
  • Wilson’s disease makes copper build up in your liver and other organs. Its first symptoms usually show up when you’re between the ages of 6 and 35, most often in your teens. It not only affects your liver, but it can cause nerve and psychiatric problems.
  • Alpha-1 antitrypsin deficiency involves a chemical that helps your lungs resist infections. Your liver makes it. But when your liver gets the recipe wrong, the faulty chemical can build up and cause liver disease.
  • Alcohol abuse can lead to cirrhosis. So can nonalcoholic fatty liver disease and long-term cases of hepatitis B and C.
  • Drug overdoses. Taking too much acetaminophen or other medications can harm your liver. Make sure you follow the dosing instructions on the label, and be aware that acetaminophen might be in more than one medicine you take.
  • Nonalcoholic fatty liver disease (NAFLD) is when too much fat has built up inside your liver. The extra fat can inflame your liver. One type of NAFLD is nonalcoholic steatohepatitis (NASH). It means you have inflammation and cell damage in your liver, as well as fat. It can scar your liver and lead to other disorders, like cirrhosis.

Dire complications of liver disease include:

  • Acute liver failure. This happens when you don’t have a long-term liver disease but your liver quits working within a very short time — days or weeks. That may happen because of an overdose of acetaminophen, infections, or because of prescription drugs.
  • Cirrhosisis a buildup of scars in your liver. The more scars replace the healthy parts of your liver, the harder it is for your liver to do its job. Over time, it may not work like it should.

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Elevated Blood ALT: Causes and Diagnosis


  • 1 Elevated Blood ALT: Causes, Symptoms, and Treatment
    • 1. 1 Elevated Blood ALT
    • 1.2 ALT: What It Is and How It Works 900 08
    • 1.3 Functions of ALT in the body
    • 1.4 Causes of elevated ALT levels
    • 1.5 Diseases that cause elevated levels of ALT in the blood
      • 1.5.1 Hepatitis
      • 1.5.2 Liver cirrhosis
      • 1.5. 3 Gallstone disease
      • 1.5.4 Aminotransferase dystrophy (ATD)
      • 1.5.5 Other diseases
    • 1.6 Symptoms of elevated blood levels of ALT
    • 1.7 Diagnosis of elevated levels of ALT
    • 9 0005 1.8 ALT tests: preparation and procedure

    • 1.9 Norm blood ALT levels
    • 1.10 Treatment of elevated ALT levels
    • 1.11 Related videos:
    • 1.12 Q&A:
        • What is ALT and what is its blood level?
        • What diseases can cause elevated blood levels of ALT?
        • Can elevated ALT be due to medication?
        • What test should be taken to determine the level of ALT in the blood?
        • 1. 12.0.5 Is it possible to determine the level of ALT in the blood?
        • What should be done if ALT is elevated in the blood?

Wondering what an elevated ALT level in a blood test means? Find out what causes this, what are the symptoms, and how you can lower your ALT levels through diet and treatment.

Alanine aminotransferase (ALT) is one of the indicators of a biochemical blood test that can signal liver damage. Elevated ALT levels can be indicative of a variety of diseases and conditions. The main thing is not to ignore this symptom and consult a doctor immediately.

Elevated blood levels of ALT can be caused by a variety of causes, including viral hepatitis, alcoholic and non-alcoholic fatty liver disease, drug poisoning, biliary obstruction, infectious diseases, and others. This indicator can also increase with prolonged physical exertion on the body, as well as during pregnancy.

In order to establish an accurate diagnosis, a comprehensive examination is required. In addition to a biochemical blood test for ALT, ultrasound and X-ray examinations of the abdominal organs, blood tests for other indicators, etc. can also be performed.

It is important to remember that spontaneous treatment can cause great harm to health. Be sure to contact only qualified doctors and follow all doctor’s prescriptions.

Elevated blood ALT

ALT (alanine aminotransferase) is an enzyme found in liver cells. When liver cells are damaged or destroyed, ALT is released into the bloodstream, causing an increase in blood levels of the enzyme.

To diagnose an elevated ALT level in the blood, it is necessary to conduct a blood test for biochemical analysis. In addition, additional tests, such as liver ultrasound or computed tomography, may be needed to determine the cause of elevated ALT levels.

  • To reduce the level of ALT, you need to see a doctor and determine the cause of the change in level.
  • Certain measures, such as avoiding alcohol, eating healthy and exercising, can help lower your ALT levels.
  • Treatment of liver diseases is based on the cause of the disease.

ALT: what it is and how it works

ALT is an enzyme that converts alanine to pyroglutamate. ALT is found within liver cells, and to a lesser extent in the heart, muscles, and other organs.

It is important to understand that ALT cannot cross cell membranes. If the level of ALT is elevated, this may indicate the destruction of the cells that contain this enzyme.

ALT is used in medical diagnostics as an indicator of damage to the liver and other organs. Elevated blood levels of ALT can indicate various diseases such as viral hepatitis, liver cirrhosis, liver cancer, as well as drug toxicity and other health conditions.

  1. ALT is an important indicator of the health of the liver and other organs
  2. Elevated levels of ALT can indicate various diseases
  3. It is important to identify the cause of elevated levels of ALT in the blood for proper diagnosis and treatment

ALT functions in the body

ALT (alanine aminotransfer aza) is an enzyme found in body tissues, especially in the liver and heart. There are several functions of ALT in the body. One of its main functions is participation in the metabolism of protein compounds, including amino acids.

In addition, ALT plays a key role in animal metabolism. It helps to remove excess ammonia, which is toxic to the body.

Changes in the level of ALT in the blood may indicate abnormalities in the functioning of the liver, heart and other organs.

Causes of elevated ALT levels

Alanine aminotransferase (ALT) is an enzyme found in the cells of the liver, heart, muscles and other organs. Its level in the blood is an indisputable marker of diseases of certain organs and tissues. Consider the main reasons for the increase in the level of ALT in the blood.

  • Liver diseases . Elevated ALT levels can be associated with various liver diseases such as hepatitis, cirrhosis, jaundice, and others. In these cases, an increase in ALT levels may be one of the first signs of the disease.
  • Alcoholism . Heavy drinking can lead to liver damage and elevated ALT levels.
  • Muscle injury . Muscle injury can lead to elevated ALT levels. Also, exercises that cause intense stress on the muscles can lead to an increase in ALT levels for a short time.
  • Medicines . Certain medications, such as aspirin, antibiotics, steroids, and others, can raise blood levels of ALT.

Remember that elevated ALT is not a disease in itself, but only a marker. Diagnosis and identification of the causes of elevated levels of ALT in the blood requires a visit to a doctor and further examination.

Diseases that cause elevated levels of ALT in the blood


An increase in the level of ALT in the blood is often associated with hepatitis – viral or alcoholic. Hepatitis is an inflammatory reaction of the liver that can lead to elevated levels of ALT in the blood. With viral hepatitis, ALT can increase by several tens of times.

Cirrhosis of the liver

Cirrhosis of the liver is a chronic disease in which healthy liver tissue is replaced by scarring, which can lead to decreased liver function. A high level of ALT in the blood can be one of the signs of cirrhosis of the liver.


In gallstone disease, stones form in the gallbladder or bile ducts, which can lead to inflammation of the liver. ALT levels may be elevated in acute or chronic inflammation of the liver associated with gallstone disease.

Aminotransferase dystrophy (ATD)

Aminotransferase dystrophy is a genetic disease that causes an increase in the level of ALT in the blood. This is due to a violation of the transfer of the amino acid alanine between cells.

Other diseases

Elevated levels of ALT may also be associated with other liver diseases, such as hepatosis (changes in the structure of the liver), liver cancer, or even heart failure.

Some diseases associated with an increase in the level of ALT Disease Description

Hepatitis Inflammation of the liver, causing an increase in the level of ALT in the blood
Cirrhosis of the liver Chron a medical disease that results in the replacement of healthy liver tissue with scarring and an increase in ALT levels
Gallstone disease Formation of stones in the gallbladder or bile ducts causing inflammation of the liver and elevation of ALT
ATD Genetic disease that causes an increase in the level of ALT in the blood
Hepatosis Change in the structure of the liver that causes an increase in the level of ALT in the blood
Liver cancers Liver cancer or metastases causing elevated ALT in the blood
Heart failure Decreased heart function causing an increase in the level of ALT in the blood

Symptoms of elevated blood levels of ALT

Elevated levels of ALT in the blood can be a symptom of various diseases and organ dysfunctions.

An increased amount of ALT may indicate the presence of viral hepatitis, cirrhosis of the liver, liver cancer, alcohol and drug intoxication, diseases of the liver, bile ducts and biliary tract. Elevated ALT levels can also be observed in people with diabetes and obesity.

If you have symptoms of elevated ALT levels in the blood, it is important to immediately consult a doctor and undergo a comprehensive examination in order to identify the cause of this condition and begin timely treatment.

Diagnosis of elevated ALT levels

Diagnosis of elevated blood ALT levels begins with a complete blood count, which is often performed during routine check-ups. If the ALT level exceeds the norm, then the doctor may prescribe additional studies.

To confirm the diagnosis and determine the cause of elevated ALT levels, more accurate tests, such as biochemical tests of blood, urine and feces, as well as ultrasound of the liver and gallbladder, may be prescribed.

  • Blood chemistry tests can help determine specific ALT levels as well as other indicators associated with liver disease;
  • Ultrasound examination of the liver and gallbladder allows you to determine possible changes in these organs and study their structure;
  • Urine and feces analysis helps to find out which metabolic products are excreted from the body;

Depending on symptoms and other factors, your doctor may order additional tests and procedures to identify the cause of your high ALT levels. The results of all these studies will help to make an accurate diagnosis and prescribe the right treatment.

ALT Tests: Preparation and Procedure

ALT testing requires preparation. Within 12 hours before blood sampling, it is recommended not to eat, and also to exclude the intake of alcohol, fatty and fried foods, and smoking. This will help avoid distorting the analysis results.

ALT results are usually available 1-2 days after blood sampling. With elevated ALT levels, additional diagnostics may be required to identify the cause of this phenomenon, but only a doctor can determine the need for such a study.

ALT blood levels

ALT (alanine aminotransferase) is an enzyme that is produced in liver cells and other body tissues. The normal level of ALT in the blood in adult men does not exceed 45 units per liter, in women – no more than 34 units per liter.

In children and adolescents, normal ALT levels may vary by age. So, in children under the age of 9 years, the normal level of ALT is no more than 50 units per liter, in adolescents aged 9 to 12 years – no more than 45 units per liter, and in boys and girls aged 12 to 18 years – no more than 55 units per liter.

It is important to note that ALT levels may vary depending on the assay methods used in the laboratory. When interpreting the results, it is necessary to take into account the specific methods and norms adopted in this laboratory.

Treatment of elevated ALT levels

If elevated ALT levels are detected, consult a physician and follow treatment recommendations. Changes in diet and a healthy lifestyle can help reduce ALT levels, but in most cases, medication will be needed.

Depending on the cause of the elevated ALT levels, different medications are used. If the cause is viral, then antiviral drugs are needed, in the case of hepatitis, the establishment of timely diagnosis, the choice of appropriate therapy and its strict implementation.

In diseases of the biliary tract, choleretic, cholelithic preparations are recommended. In the presence of tumor processes, only surgical treatment can normalize the level of ALT. Additional recommendations for treatment should be prescribed by the attending physician.

It is not recommended to stop taking medications without your doctor’s consent.

  • Drug treatment should be carried out under medical supervision.
  • Do not mix drugs with alcohol to avoid additional damage to the liver.
  • It is important to take care of your health and have regular medical check-ups.

If you experience pain in the right hypochondrium, weakness, fever, swelling and jaundice, you should immediately consult a doctor.

Video on the topic:


What is ALT and what is its norm in the blood?

ALT (alanine aminotransferase) is an enzyme that is found inside the liver cells and is responsible for the metabolism of amino acids in the body. The norm of ALT in the blood in men is 10-40 U / l, and in women – 7-35 U / l. However, with various diseases, the norm may deviate upwards.

What diseases can cause elevated blood levels of ALT?

Elevated ALT levels may be associated with liver disease (hepatitis, cirrhosis, fatty degeneration), heart disease (heart attack, arrhythmia), problems with the external bile duct, and other diseases associated with impaired amino acid metabolism (eg, diabetes).

Can elevated ALT levels be related to medication?

Yes, some medications can increase ALT levels in the blood, such as anti-tuberculosis drugs, antivirals, steroids, anti-cancer drugs, antibiotics, etc. Therefore, you should tell your doctor that you are taking any medications before testing.

What test should be taken to determine the level of ALT in the blood?

A blood chemistry test is required to determine the level of ALT in the blood. Usually, this test is prescribed in combination with other tests, such as a complete blood count, bilirubin level, AST, etc.

Can I determine the level of ALT in the blood myself?

No, the determination of the level of ALT in the blood is possible only when donating blood in a medical institution and conducting an appropriate analysis. It is impossible to independently determine the level of ALT in the blood.

What should be done if ALT is elevated in the blood?

If ALT levels are elevated, you should see a doctor to diagnose the disease that caused this deviation. Depending on the cause of the elevated ALT level, your doctor will prescribe the appropriate treatment.

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.

A 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. In a healthy body, the content of ALT in the blood is insignificant.

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ALT increased during pregnancy

In women, the amount of alanine aminotransferase is limited to 31 U/L. However, in the first trimester of pregnancy, a slight excess of this value is possible. This is not considered a deviation and does not indicate the development of any disease. In general, ALT and AST levels should be stable throughout pregnancy.

A slight increase in the number of enzymes of this group is observed in gestosis. In this case, they have a light or medium severity.