Gama GT Exam (GGT): what it is, high, low and what it is for


What is GT range?

Gamma GT (gamma glutamyl transpeptidase or GGT) is the blood test that measures the amount of the enzyme gamma glutamyl transferase (GGT) in the body. This enzyme is present mainly in the liver and bile ducts, but it can also be found in the cells of the kidneys, intestines, pancreas and spleen.

The test serves especially to provide an analysis of the functioning of the liver and to identify possible liver changes, especially those related to alcohol consumption.

In some cases, it can detect bile duct obstruction.

When any of the organs that contain GGT does not work satisfactorily, the amount of the enzyme in the blood may change, showing some functional failure of the organism and allowing clinical investigation to identify the cause and, thus, carry out the treatment.

Because this enzyme is found in different parts of the body, the test may not be able to specify in isolation which organ is having problems, which may require the request for further tests.

How is done?

The GT range is a laboratory test performed by means of blood collection by venipuncture of approximately 5mL, similar to the collection performed in the blood test .

The test is done in a few minutes, does not cause major complications and does not require hospitalization.

Your results come out in approximately 24 hours.

When is it requested?

In most cases, the GT range is ordered in patients with suspected liver problems, such as cirrhosis and hepatitis or excessive alcohol use.

However, the doctor may also recommend the test when he identifies a high level of alkaline phosphatase, indicative of low vitamin D, suspected pancreatitis , among others.

Some indications of abnormal liver function include:

  • Stools with lighter or whitish colors;
  • Dark urine;
  • Nausea accompanied by vomiting;
  • Pain or swelling in the abdomen;
  • Sudden weight loss;
  • Swelling in the legs or ankles;
  • Loss of appetite;
  • Itches;
  • Jaundice (yellowish color on the skin or eyes);
  • Weakness;
  • Excessive fatigue;
  • Digestive bleeding.

After all, what is alkaline phosphatase?

Alkaline phosphatase (ALP) is also an enzyme, which has a direct relationship with the GT range and can be found in the liver system and bones. Elevated levels of this enzyme may indicate disturbances in bone activity, as well as liver changes that affect the bile ducts.

For this reason, it is quite common for the alkaline phosphatase test to be complementary to the GGT test.

In cases of diseases of the bile ducts and liver, the levels of ALP and GGT will be high. However, in situations of high ALP and normal GGT, bone disease is likely.

GGT and alcoholism: what is the relationship?

Even in small quantities, alcohol consumption raises the levels of the GGT enzyme in the blood. For this reason, the GT gamma test can be used to screen or monitor alcohol use / abuse in patients undergoing treatment for alcoholic hepatitis and alcoholism .

It is worth noting that in about 75% of chronic drinkers, the level of the enzyme will be high.

Pre-examination care

Some guidelines before taking the exam are:

  • Suspend alcohol or cigarette intake 24 hours before the exam;
  • Not having had a liver biopsy in the last 5 days;
  • Be fasting for at least 8 hours (confirmation with the laboratory that will perform the procedure is necessary, as your need may vary).

The doctor may also request the suspension of some medications that tend to alter the test result , such as:

  • Hidantal ,
  • Phenytoin ,
  • Carbamazepine ,
  • Non-steroidal anti-inflammatory drugs,
  • Antibiotics,
  • Antiallergic,
  • Antifungal,
  • Antidepressants,
  • Contraceptives,
  • Testosterone-based drugs.

Therefore, it is very important to inform the health professional about the medications used.

Results of

As the reference values ​​of the GT range may vary depending on the laboratory, it is essential to present the results for analysis with the doctor. Generally, the values ​​considered normal are between 8 to 61 U / L (men) and 5 to 36 U / L (women).

High GT range

The rise in GGT suggests that some disease or condition is damaging the liver, and generally the higher this result, the greater the damage. The factors that justify the increase include:

  • Viral hepatitis (hepatitis A, hepatitis B or hepatitis C);
  • Medicated or alcoholic hepatitis;
  • Toxic hepatitis;
  • Autoimmune hepatitis;
  • Abuse of alcoholic beverages, cigarettes, medicines or other drugs;
  • Cirrhosis;
  • Obstruction of the bile ducts;
  • Use of some medications;
  • Diabetes;
  • Liver steatosis (fat in the liver);
  • Inflammation in the liver;
  • Acute myocardial infarction (approximately 4 to 10 days after the episode);
  • Hyperthyroidism etc.

How to decrease?

The main factor for the reduction of the GT range is the identification of the cause of this increase, such as cutting or reducing alcohol consumption, performing medication substitution and treating the diseases that cause it.

The professionals responsible for the treatment of the clinical condition are the gastroenterologist or hepatologist. In cases of viral hepatitis, there may also be a need for follow-up by an infectious disease specialist.

Care to avoid elevation of GGT

Paying attention to simple habits to prevent the elevation of the GT range can also help in the prevention of other health problems. Care includes:

  • Practice of physical activity;
  • Balanced diet, consuming all food groups (proteins, fibers, carbohydrates);
  • Avoid the consumption of alcoholic beverages and cigarettes;
  • Introduce foods rich in omega 3 and anti-inflammatory foods;
  • Reduce the consumption of fats and sugars.

Low GT range

A low value as a result of the GT range indicates improbability of liver problems and alcohol consumption. However, if associated with a high level of alkaline phosphatase, it may be indicative of vitamin D deficiency, Paget’s disease or bone disease.


Because it is a blood collection, the risks of the GT gamma test are few, and may include:

  • Bleeding at the location of the syringe insertion (needle);
  • Dizziness;
  • Drop in blood pressure (hypotension);
  • Fainting;
  • Infection (rare).

Common questions

Does high GGT always show symptoms?

The increase in GGT in many cases can be asymptomatic, that is, it does not present any symptoms. This condition may be temporary, as in the case of alcohol consumption or use of medications.

If other enzymes do not change, the doctor may order a new test to confirm the result and perform a temporary increase analysis or the cause of the elevation.

Does the GGT level return to normal when you stop drinking alcohol?

Abstaining from alcohol will cause the GGT level to return to normal over time. However, in cases of alcoholism, this change can take weeks or months. This will also allow liver function to improve.

Complementary exams

There are cases where some additional tests are needed in order to identify the cause of the increase in GT range rates:

  • CBC: performs the analysis of blood parameters;
  • Tests for identification of liver and biliary functions: the most common include the tests for alkaline phosphatase, bilirubin alanine transaminase (ALT), lactic dehydrogenase, albumin, prothrombin time;
  • Type 1 urine test: analyzes the indicators of glucose, proteins, leukocytes and erythrocytes, which indicate the functionality of the kidneys;
  • Uroculture: as well as the type 1 urine test, evaluates the functioning of the kidneys;
  • Tumor marker CA 19-9: used in patients with suspected pancreatic cancer or other conditions, such as pancreatitis;
  • Amylase: responsible for the identification of pancreatitis;
  • Colonoscopy: checks for cancer in the small and large intestines;
  • Ultrasonography or tomography: carries out the study of enlarged spleen.