Your liver is a remarkable, hardworking organ. It is quietly yet tirelessly taking care of crucial biological tasks like detoxifying your body, breaking down foods, and supporting your immune system. 

But unlike other parts of your body, you can’t easily tell if your liver is healthy just by how you feel. 

That’s why getting Liver Function Tests (LFTs) at regular intervals are so important. 

These are straightforward blood tests that can give you early warnings, helping you and your doctor understand your liver health, spot potential conditions, and ensure it continues performing at its best.

We’ll break down everything you need to know about Liver Function Tests, why they’re vital, what to expect, and how to interpret your results clearly. 

Key Takeaways:

  • Early Detection: Liver Function Tests (LFTs) are essential for catching liver issues early, significantly improving health outcomes.
  • Simple & Quick Procedure: LFTs involve easy blood draws, with minimal discomfort and rapid results.
  • Common Indicators: LFTs measure key enzymes (ALT, AST), proteins (Albumin), and waste products (Bilirubin), that show vital information on liver health.
  • Abnormal Results: Results outside normal ranges don’t necessarily mean severe conditions but you should get further medical evaluation.
  • Proactive Care: Regular monitoring and open communication with your doctor help maintain your liver’s health and overall well-being.

What Are Liver Function Tests?

Liver function tests measure certain enzymes, proteins, and waste products in your blood. 

These results help healthcare professionals assess how well your liver functions, pinpoint potential problems, and evaluate the impact of medications you’re taking.

Common Liver Function Tests Explained

Here’s a friendly breakdown of the most common tests your doctor might perform:

  • Alanine Transaminase (ALT): High levels can suggest liver cell damage or inflammation.
  • Aspartate Transaminase (AST): Elevated levels often signal liver injury or inflammation.
  • Alkaline Phosphatase (ALP): Higher than usual levels may indicate bile duct blockage or liver problems.
  • Gamma-glutamyl Transferase (GGT): Helps identify if elevated ALP levels are due to liver or bone issues.
  • Bilirubin: Measures how efficiently your liver clears waste products. Elevated bilirubin may cause jaundice and indicate liver dysfunction.
  • Albumin and Total Protein: Low levels might suggest your liver isn’t producing enough protein, a sign of possible damage.
  • Prothrombin Time (PT): Checks blood clotting speed; prolonged clotting time can indicate impaired liver function.

What kinds of things can a liver panel tell you?

Different values and ratios of different substances may tell your healthcare provider:

  • If you have liver inflammation (hepatitis)
  • Whether the inflammation is alcohol-related or nonalcoholic (metabolic)
  • Whether you have a problem in your liver itself or in your bile ducts
  • If your liver function is impaired, and if so, how much
  • If your bile flow is impaired, and if so, how much
  • Whether your medications are affecting your liver, and if so, how much

Test Details

How do liver function tests work?

A healthcare provider draws a small amount of blood from a vein in your arm to test in the lab. They’ll look for abnormally high or low levels of different substances. 

Often, they’ll want to compare levels of different enzymes or proteins to each other. If the balance is off, that can help them understand better what may be going on in your liver.

What happens during the test?

You may have the test at a hospital or a specialized testing facility. Your healthcare technician will locate the vein in your arm that they’ll use to draw blood from and then clean the site. 

They may wrap your arm with a compression band to make your veins stick out. They’ll insert a small needle into your vein and draw blood into a vial. It only takes a few minutes.

What happens after?

Your technician will send your blood sample to a lab for analysis. The lab may be in the same facility or a different one. 

This may determine how fast your results come back. 

It may be a few hours or a few days. As long as you aren’t feeling lightheaded from the blood draw, you can go home now, resume your medications and have something to eat and drink.

Results and Follow-Up

How do I interpret the results of my liver function test?

When you get your test results back, you’ll see different values listed for different substances that were measured. You’ll be able to compare low or elevated levels against normal values. 

But what do these numbers mean?

Interpretation of your liver function test takes some skill. Your healthcare provider will walk you through your results and how to read them.

What to Expect During Your LFT

The procedure is quick, simple, and typically painless. A healthcare provider will draw a small sample of blood from your arm, usually taking only a couple of minutes. 

You might feel a slight pinch, but any discomfort is generally minimal. Test results usually become available within a few hours to a few days.

Understanding Your LFT Results

Here are typical healthy ranges for LFT components:

  • ALT: 0–45 IU/L
  • AST: 0–35 IU/L
  • ALP: 30–120 IU/L
  • GGT: 0–30 IU/L
  • Bilirubin: 2–17 micromoles/L
  • Albumin: 40–60 g/L
  • Total protein: 3–8 g/dL
  • Prothrombin Time (PT): 10.9–12.5 seconds

If your results fall outside these ranges, it doesn’t automatically mean there’s a severe issue, but it does warrant further evaluation:

  • High AST and ALT Levels: Typically indicate liver cell injury or inflammation. Equal elevations usually suggest non-alcoholic causes like infections or toxins, while an AST level significantly higher than ALT can indicate alcohol-related liver injury.
  • Elevated ALP or Bilirubin: May point to bile duct obstruction or liver dysfunction.
  • Extended PT: Suggests impaired liver function or decreased protein production

What can a liver function test diagnose?

These blood tests may not be enough to decisively diagnose a specific liver disease, but they can point your healthcare provider in the right direction and help rule out other possibilities. You might need further tests, such as imaging tests, a liver biopsy or blood tests for specific viruses to help make your final diagnosis. Possible diagnoses may include:

  • Fatty liver disease
  • Toxic hepatitis
  • Autoimmune hepatitis
  • Viral hepatitis (A, B or C)
  • Hemochromatosis
  • Wilson’s disease
  • Alpha-1 antitrypsin deficiency
  • Primary biliary cholangitis (PBC)
  • Cirrhosis
  • Liver cancer

How Often Should You Get Liver Function Tests (LFT)?

For Healthy Individuals:
If you’re in good health with no known liver issues, getting an LFT once a year should be a part of your routine health check-up.

For High-Risk Groups:
If you fall into any of the following categories, you may need LFTs every 6 months or as advised by your doctor:

  • Heavy alcohol consumers
  • People with obesity or diabetes
  • Those on long-term medications
  • Individuals with a family history of liver disease

For Diagnosed Liver Conditions:
If you already have a liver condition (e.g., hepatitis, cirrhosis, or fatty liver), your doctor may recommend LFTs every 3 to 6 months to monitor your liver’s health and the effectiveness of your treatment.

Conclusion

Our liver is an amazing organ, like all other body parts, and plays a vital role in our healthy living.

Regular liver health tests, exercises, and healthy eating can help you maintain optimal liver function, prevent diseases, and ensure a healthier, happier life.

We hope this blog helped you learn about your liver and how you can prioritize your liver health. For more health tips and insights, follow us on social media and explore our other blogs. 

Stay informed, stay healthy!