Liver Function Test: Identifying 4 Warning Signs of Liver Damage

Liver function tests (LFTs) are a set of blood tests used to assess the well-being of your liver. These tests can evaluate the liver's condition by analyzing the levels of liver enzymes, proteins, and bilirubin in the blood.

LFTs also help in monitoring the progression or treatment of an existing illness. Elevated or reduced levels of these enzymes or proteins in specific tests can indicate a liver problem. These tests are conducted for a range of reasons, such as the detection of diseases like hepatitis, monitoring the potential side effects of medications, and assessing the severity of liver disease.

When is a liver function test required?

A liver function test is commonly suggested in the following circumstances:

1. To evaluate potential damage from liver infections, such as hepatitis B and hepatitis C, especially if exposure to a virus-causing hepatitis is suspected.
2. To monitor the adverse effects caused by certain medications, such as:

• Non-steroidal anti-inflammatory drugs (NSAIDs)
• Statins
• Antibiotics
• Antiseizure medications
• Tuberculosis medications

1. If you have already been diagnosed with liver disease, to regularly monitor the progression of the disease and assess the treatment effectiveness. Doing this will aid in evaluating the overall health of your liver and success of a specific treatment approach.
2. If you consume alcohol regularly
3. If you are diagnosed with gallbladder disease
4. In case you have particular medical conditions, for example:

• High triglycerides
• Diabetes
• High blood pressure
• Anemia

Warning signs of liver damage

An unhealthy diet and sedentary lifestyle are among the leading causes of liver damage. In the early stages, liver damage can be managed through medication and making necessary changes to one's lifestyle. If the situation gets worse, a liver transplant may be necessary to restore the liver's functionality. To prevent such complications, it is important to pay attention to the following warning signs of liver damage and not disregard them.

• Fluid retention
• Jaundice
• Bruising
• Nausea and loss of appetite
• Abdominal pain and swelling

What does liver function test measure?

A liver panel includes the following tests:

Aspartate aminotransferase (AST): AST plays a role in the metabolism of amino acids. High AST blood levels can be a sign of liver damage or disease.

Alanine aminotransferase (ALT): ALT is another enzyme that helps break down proteins and is found primarily in the liver. High blood levels of ALT may indicate liver damage.

Alkaline phosphatase (ALP): ALP is an enzyme found in liver, bile ducts, and bone. You may have high levels of ALP if you have liver damage or disease, a blocked bile duct, or bone disease.

Bilirubin: Bilirubin is generated during normal break down of red blood cells. Normally, it is processed by the liver in your body. Higher than normal levels of bilirubin may indicate liver disease or damage.

Albuminand total protein: Albumin is one of the many proteins made in the liver. Your body uses this protein to fight infections and to perform other functions. Reduced levels of albumin and total protein may suggest the presence of liver damage or disease.

Gamma-glutamyl transferase (GGT): GGT is an enzyme made by the liver and high levels of this enzyme may indicate liver or bile duct damage.

L-lactate dehydrogenase (LD): LD is an enzyme in the liver. Elevated levels of this enzyme may suggest liver damage, although they can also be increased in various other medical conditions.

Prothrombin time (PT): PT is the time taken by your blood to clot. Elevated PT levels may suggest liver injury, but they can also be raised due to the use of certain blood-thinning medications.

Test procedure

A blood sample is drawn from a vein in your arm. The healthcare provider will tie a band around your upper arm to help locate your veins. After that, an antiseptic wipe will be used to clean a small area of skin. Then, the needle will be inserted into your vein and a small amount of blood will be drawn. The blood sample will then be sent to a laboratory for analysis.

Before undergoing the LFT test, you should fast for 10–12 hours. You have to let your healthcare provider know about all the medications you are currently taking, since they can affect the accuracy of the test results.

Interpretation of liver function test results

Deviation from normal levels indicates the following:

• Higher than normal ALT can be a sign of liver damage. Very high levels are most often caused by viral hepatitis, ischemic hepatitis, or injury from drugs or other chemicals.
• Higher than normal AST may be because of a problem with your liver or muscles. An elevated AST level without a corresponding elevation in ALT levels could suggest the presence of heart or muscle disease. However, if ALT, bilirubin, and ALP levels are all elevated, it may indicate potential liver damage.
• Elevated levels of ALP may be a sign of liver inflammation, blockage of the bile ducts, or bone disease.
• Lower than normal albumin may indicate that the liver is not functioning properly. This occurs in diseases such as cirrhosis of the liver, malnutrition, and cancer.
• Higher than normal bilirubin may indicate that the liver is not functioning properly. Elevated bilirubin levels with elevated ALT or AST levels may indicate cirrhosis or hepatitis.
• Higher than normal GGT may indicate damage to the liver or bile ducts.
• Elevated levels of LD or PT may indicate liver damage.

It is advisable to consult with your healthcare provider in order to understand your specific test result and determine the appropriate treatment approach.

Liver function tests are used to assess liver health through blood analysis. Changes in protein and/or enzyme levels can imply conditions such as liver cancer, fatty liver disease, and hepatitis. These tests also can help to find out whether certain medications are causing harm to the liver or help to monitor the status of a liver disease progression.