AST- Aspartate Aminotransferase Test

What is AST?

AST stands for aspartate aminotransferase which is one of the two enzymes produced by the liver. AST also is known as an SGOT or serum glutamic-oxaloacetic transaminase and the protein is found mostly in the liver and other parts of the body like muscles, heart, brain, and kidneys.

When our liver gets damaged or the muscles, brain, heart, or kidneys are not functioning properly AST leaks into the bloodstream and the AST levels get elevated.

What is an AST test?

An AST is a blood test that helps to measure the amount of AST in the blood. The test is often done as a part of a routine blood screening test or to diagnose liver diseases or damage.

Does this test have any other name?

Yes, the other names of the AST test are:
– SGOT test.
– Serum glutamic oxaloacetic transaminase test.
– Aspartate transaminase test.

Why do I need an AST test?

Your doctor may prescribe an AST blood test if you are experiencing the following symptoms of liver disease:

– Nausea or vomiting.
– Sudden loss of appetite.
– Swelling in ankles, legs, and abdomen.
– Jaundice or yellowish discoloration of skin and eyes.
– Light-colored stool.
– Dark urine.
– Pruritus or persistent itching of skin.

Your doctor may also order an AST test if he thinks you are at risk of liver diseases. The factors governing liver diseases include:

– Drug abuse.
– Heavy alcohol intake.
– Family history of liver diseases.
– Family history of diabetes.

You may also undergo an AST test if you are suffering from an existing liver disorder. Your doctor may need the test to monitor your progress and to see the effectiveness of your medications. The AST test is also done if your doctor suspects that a medication is causing damage to your liver. In other cases, doctors may also order an AST test if you are suffering from any of the below medical conditions:
 
– Kidney damage
– Excessive iron in blood or hemochromatosis
– Blood cancer 

How should I prepare for an AST test?

No special preparations are needed for an AST blood test. If your doctor has prescribed other blood tests along with your AST test, you may have to fast for a few hours before the test. If you are taking any medication or have a medical condition, you need to inform about the same to your doctor before taking the test. Any other instructions shall be informed to you by your technician.

Do I need to fast before an AST test?

If you are doing other blood tests along with your AST test, then you need to stop eating food or take any other liquid a few hours before the test.

How is the AST test done?

The AST test is very simple just like a regular blood test. Your health care provider will follow the simple steps to administer the test.

– The technician will first clean a patch of the skin with an antiseptic solution.

– A tourniquet or elastic band is then tied around the arm to swell up the vein. This makes the veins more visible and helps to draw the blood.

– After the technician finds the vein, he will insert a needle attached to a syringe or vial to draw the sample of blood.

– The blood sample is then pulled into a vial or syringe.

– The needle is removed.

– The elastic band is removed.

– A clean cotton swab is put on the puncture site to prevent bleeding.

– The technician will then send the blood sample to the laboratory for evaluation.

Can infants and children undergo an AST test?

Yes, infants and children can undergo an AST test and it is completely safe. In babies, the AST test is often done through the “heel-stick” process. Here, the health provider will clean an area on the heel of your baby. He will insert a small needle or lancet on the heel and draw out a small sample of blood. The procedure is done very quickly, and your baby will feel pain only for a little while.

In older children, the blood is collected from the veins and your child may feel a temporary discomfort. Parents can stay with their children to make them comfortable during the whole procedure.

How long will it take to complete the test?

The test will be completed within a few minutes.

Is there any risk of the AST test?

There are no risks to the AST test. There might be slight pain or bruising around the site of the puncture, but it will go away within a day or two. Some people may experience certain difficulties after the blood test such as:

– Excessive bleeding from the puncture site.
– Fainting or lightheadedness.
– Hematoma or blood accumulation under the skin.
– Infection or swelling around the puncture site.

If you experience any of the above symptoms, you may immediately consult a medical practitioner.

Can a pregnant woman undergo an AST test?

Yes, a pregnant woman can undergo an AST test. The AST and ALT (alanine transaminase) levels are not elevated during normal pregnancies. However, if a pregnant woman is suffering from AFLP (acute fatty liver of pregnancy) or IHCP (intrahepatic cholestasis of pregnancy), this can trigger other liver diseases like viral hepatitis or Wilson’s disease. In such a case, doctors may ask patients to undergo an AST test along with other liver function tests.

What is the cost of the AST test in India?

The average cost of the AST test in India may vary from INR 50 to INR 470 depending on the city, availability, laboratory, and the quality of the test.

When will I get my AST test results?

You will get your test results within a day.

What is the normal range of AST?

The normal range of AST may vary according to age, gender, medical history, diet or other medical conditions. An abnormal test result does not necessarily mean that you have a problem, it may also depend on the laboratory and other factors.

It is always advisable to consult a medical practitioner who will explain to you the meaning of your result. The normal range of the AST level is given below.

High or low levels of AST indicates that you are suffering from some liver disease and need medical attention. Any level other than the normal range can be a matter of concern but does not necessarily mean you have a medical problem. The results of AST may vary due to several factors such as:

– Older age.
– Medical history.
– Medicines like antibiotics
– Diet
– Medical history

If your AST levels are abnormally high, they may be suggestive of the following conditions:

– Cirrhosis of the liver
– Injury in muscle.
– Heart problems.
– Shock liver.
– Celiac disease.
– Hepatitis
– Mononucleosis
– Pancreatitis
 

What are the limitations of the AST test?

The AST test has certain limitations such as:

– The report may come out as false-positive if you are suffering from diabetic ketoacidosis.

– May give false report especially if you are under any antibiotic.

– The test results may vary due to pathological errors.

– Many patients who are suffering from acute liver diseases or hepatitis C infection may show normal AST levels. So, doctors often order other liver function tests along with AST to determine the medical conditions.

What other tests can be done along with AST?

If your AST test results are not conclusive, your doctor may order other liver function tests such as ALT, alkaline phosphatase, bilirubin, albumin, etc.