SGOT (AST) Test

When a doctor observes any of the following symptoms, he/she might advise liver function tests:

• Jaundice
• Abdominal discomfort or pain
• Vomiting and nausea
• Dark-coloured urine despite adequate water intake
• Weakness and loss of appetite

Along with AST, liver also produces other chemicals and proteins, which are all released in the blood upon liver damage. Alanine aminotransferase is one such protein. Therefore, in order to confirm liver damage as a cause for elevated AST levels, a doctor might order for a check of ALT levels too.

SGOT (AST) is a blood test for evaluating the levels of AST in blood. No preparation is needed for this test. However, the doctor should be informed of a past history of illnesses, any past or current medication or herb intake, or if the individual is pregnant.

A blood sample is collected at any time of the day from a vein in the patient’s arm with the help of a sterile syringe. A slight discomfort might be felt at the needle prick site. Once blood sample is collected, it is deposited into a sterile vial. The whole procedure takes less than 5 minutes. Some patients may feel mild light-headedness for a few seconds, which may disappear soon.

Normal results:

On average, under normal healthy conditions, AST levels in blood remain low. Normal AST levels are:

• 14-20 units/litre in males
• 10-36 units/litre in females

Although the absolute values of AST may differ from one laboratory to another depending on the standardization protocols followed.

Individuals in higher age groups can have slightly higher than normal levels of AST.[3] When an ALT test is run in parallel to AST, their ratio is of prime importance. Under normal conditions,  AST/ALT ratio is equivalent to 1.

Abnormal results:

The following conditions could lead to a high level of AST:

• Chronic conditions
  • Gallstones
  • Tumour in liver
  • Alcoholism
  • Diabetes
  • Kidney and lung illness
  • Heart failure
• Acute conditions
  • Side effects of antibiotics and nonsteroidal anti-inflammatory drugs
  • Higher intake of some herbal supplements like kava, dandelion and comfrey
  • Infectious hepatitis
  • Muscle over-exertion

Increased AST by itself does not indicate liver damage or any particular organ damage. Therefore, AST/ALT ratio is considered to be more useful. A ratio of more than 1 indicates heart and muscle damage, as AST levels can rise 3-5 times of normal in these cases. Some cases of infectious hepatitis, cirrhosis and alcoholic hepatitis could also have such ratios. If the ratio is less than 1, it could indicate some form of liver damage, although further tests may be required to confirm the nature of damage.

Disclaimer: All results must be clinically correlated with the patient’s complaints to make a complete and accurate diagnosis. This information is purely from an educational point of view and is in no way a substitute for medical advice by a qualified doctor.