The ALT test contains 1 test with 1 biomarker.

Description: An Alanine Aminotransferase Test is a blood test that is used to screen for and diagnose liver disease.

Also Known As: Alanine Aminotransferase Test, Alanine Transaminase Test, GPT Test, SGPT Test, Serum Glutamic Pyruvic Transaminase Test

Collection Method: Blood Draw

Specimen Type: Serum

Test Preparation: No preparation required

Average Processing Time: 1 to 2 days

When is an Alanine Transaminase test ordered?

When a person undergoes a standard health examination, ALT may be ordered as part of a full metabolic panel.

When a person has signs and symptoms of a liver problem, a healthcare provider will usually prescribe an ALT test.

Because many people with minor liver damage have no signs or symptoms, ALT may be ordered alone or in combination with other tests for persons who are at an elevated risk for liver disease. With modest liver injury, ALT levels will rise even if there are no other symptoms.

ALT may be ordered on a frequent basis during the course of treatment to establish whether the medication is effective when it is used to monitor the treatment of persons with liver disease.

What does an Alanine Transaminase blood test check for?

Alanine aminotransferase is an enzyme found mostly in liver and kidney cells. It's also found in much lesser concentrations in the heart and muscles. This test determines the amount of ALT in your blood.

The enzyme ALT converts alanine, a protein amino acid, into pyruvate, an important intermediary in cellular energy production. ALT levels in the blood are low in healthy people. ALT is released into the bloodstream when the liver is injured, frequently before more evident indications of liver injury, such as jaundice, appear. As a result, ALT is a useful test for detecting liver disease early on.

The liver is a critical organ positioned directly behind the rib cage on the upper right side of the abdomen. It is engaged in a variety of vital bodily functions. The liver aids in the digestion of nutrients, creates bile to aid in fat digestion, produces a variety of essential proteins such as blood clotting factors and albumin, and breaks down potentially hazardous compounds into safe substances that the body may utilize or discard.

Damage to liver cells can be caused by a variety of factors, resulting in an elevation in ALT. The test is most useful for detecting damage caused by hepatitis or medications or other toxins that are harmful to the liver.

As part of a liver panel, ALT is frequently tested alongside aspartate aminotransferase, another liver enzyme. When the liver is injured, both ALT and AST levels rise, albeit ALT is more specific for the liver and may be the only one to rise in some circumstances. An AST/ALT ratio can be used to help distinguish between different types of liver injury and their severity, as well as to distinguish liver injury from heart or muscle damage.

Lab tests often ordered with an Alanine Transaminase test:

  • AST
  • ALP
  • GGT
  • Bilirubin
  • Liver Panel
  • Comprehensive Metabolic Panel
  • Albumin
  • Total Protein
  • Prothrombin Time
  • Hepatitis Panel General

Conditions where a an Alanine Transaminase test is recommended:

  • Liver Disease
  • Hepatitis
  • Jaundice
  • Cirrhosis
  • Alcoholism
  • Wilson Disease
  • Hemochromatosis

How does my health care provider use an Alanine Transaminase test?

The alanine aminotransferase test is commonly used to diagnose liver damage. It's frequently ordered as part of a liver panel or complete metabolic panel with aspartate aminotransferase to screen for and/or diagnose liver disease.

ALT is an enzyme found mostly in liver and kidney cells. ALT is released into the bloodstream when the liver is injured. As a result, ALT is a useful test for detecting liver disease early on.

Although ALT is more specific to the liver than AST, they are both considered to be two of the most significant tests for detecting liver impairment. When AST is directly compared to ALT, an AST/ALT ratio is calculated. This ratio can assist distinguish between different types of liver disease and identify cardiac or muscle harm.

To assess which type of liver illness is present, ALT values are frequently matched to the results of other tests such as alkaline phosphatase, total protein, and bilirubin.

ALT is frequently requested to monitor the therapy of people with liver disease to evaluate if it is effective, and it can be ordered alone or in combination with other tests.

What do my ALT test results mean?

A low ALT level in the blood is normal and anticipated. The most prevalent cause of ALT levels that are higher than normal is liver disease.

Acute hepatitis and viral infections are the most common causes of very elevated ALT values. ALT levels are normally elevated for 1-2 months after acute hepatitis, but they might take up to 3-6 months to return to normal. ALT levels may also be significantly raised as a result of exposure to liver-toxic medications or other chemicals, or in situations that produce reduced blood flow (ischemia) to the liver.

In chronic hepatitis, ALT levels are frequently less than four times normal. Because ALT levels in this scenario regularly fluctuate between normal and slightly elevated, the test may be ordered frequently to observe if a trend emerges. Other reasons of mild ALT elevations include bile duct obstruction, cirrhosis, heart damage, alcohol addiction, and liver cancers.

ALT is frequently used in conjunction with an AST test or as part of a liver panel. See the Liver Panel article for more information on ALT values in relation to other liver tests.

The ALT level is usually greater than the AST level in most forms of liver disorders, and the AST/ALT ratio is low. There are a few exceptions: in alcoholic hepatitis, cirrhosis, and heart or muscle injury, the AST/ALT ratio is frequently more than 1, and it may be greater than 1 for a day or two after the onset of acute hepatitis.

We advise having your results reviewed by a licensed medical healthcare professional for proper interpretation of your results.

The following is a list of what is included in the item above. Click the test(s) below to view what biomarkers are measured along with an explanation of what the biomarker is measuring.


Alanine transaminase (ALT) is an enzyme found in the highest amounts in the liver. Injury to the liver results in release of the substance into the blood.
*Process times are an estimate and are not guaranteed. The lab may need additional time due to weather, holidays, confirmation/repeat testing, or equipment maintenance.

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