You’ve been advised to get a liver function test, or perhaps you’re experiencing symptoms that make you wonder about your liver health. It’s natural to have questions about what this involves.
Liver function tests (LFTs) or liver panel tests are essential blood tests that provide crucial insights into how well your liver is working. They help detect inflammation, injury, and problems with bile flow—all of which may require medical attention.
This guide walks you through everything you need to know about LFTs, from why they’re done to understanding your results. Whether you’re undergoing a liver function test in Singapore or simply want to understand more about liver health, this step-by-step guide is designed to help you feel informed and prepared.
Step 1: Why Are Liver Function Tests Recommended? (When to Get One)
The primary purpose of an LFT is to assess your liver’s overall health by measuring the levels of specific enzymes and proteins in your blood. These markers can help a doctor detect liver inflammation, injury, or issues with its function, sometimes even before symptoms appear.
A doctor may recommend a liver function test for several common reasons:
- Symptoms of Liver Issues: If you are experiencing persistent fatigue, nausea, unexplained weight loss, dark-coloured urine, yellowing of the skin or eyes (jaundice), or pain in the upper right abdomen, an LFT is a critical first step in diagnosis.
- Monitoring Existing Conditions: For individuals already diagnosed with liver conditions like non-alcoholic fatty liver disease (NAFLD/MASLD), hepatitis B or C, or cirrhosis, regular LFTs are essential to monitor disease progression and treatment effectiveness.
- Medication Monitoring: Certain long-term medications can affect the liver. LFTs help monitor for potential drug-induced liver injury, ensuring your treatment plan remains safe.
- Routine Health Screenings: A liver panel test is often included in comprehensive health check-ups to proactively assess your general liver wellness as part of preventative care.
Step 2: What Do Liver Function Tests Measure? (Common Terms & What They Test For)
Understanding the meaning of your LFT results involves knowing what each component of the test measures. The liver panel test typically includes the following key markers:
Liver Enzymes (Indicators of Damage or Inflammation):
- ALT (Alanine Aminotransferase): This enzyme is found primarily in the liver. Elevated ALT levels are often a specific indicator of liver cell damage or inflammation.
- AST (Aspartate Aminotransferase): AST is found in the liver but also in other organs like the heart and muscles. Elevated levels can also indicate liver damage, though it is less specific than ALT.
- ALP (Alkaline Phosphatase): This enzyme is concentrated in the liver, bile ducts, and bone. High ALP levels can suggest liver disease, a blockage in the bile ducts, or certain bone disorders.
- GGT (Gamma-Glutamyl Transferase): GGT is another enzyme that can indicate bile duct problems or liver damage. Its levels are often elevated with excessive alcohol consumption.
Proteins (Indicators of Liver Function):
- Albumin: This is a major protein produced by the liver. Low albumin levels can signal that the liver isn't functioning properly, which may occur in chronic liver disease.
- Total Protein: This measures albumin and all other proteins in the blood, giving a general sense of your nutritional status and liver function.
Bilirubin (Indicators of Bile Flow and Liver Processing):
- Total Bilirubin: Bilirubin is a yellow substance formed from the breakdown of red blood cells. The liver processes it for excretion. Elevated total bilirubin levels cause jaundice and can indicate that the liver is not clearing it effectively.
- Direct & Indirect Bilirubin: Measuring these specific forms of bilirubin helps a doctor pinpoint whether the problem is due to liver cell disease or other causes like red blood cell breakdown.
Step 3: What's the Liver Function Test Procedure Like?
The procedure for a liver function test is simple, safe, and straightforward.
- Preparation: Before the test, your doctor will provide specific instructions. You may be asked to fast (not eat or drink anything except water) for 8 to 12 hours beforehand, as some foods can temporarily affect your results. It is also important to discuss any medications or supplements you are currently taking with your doctor, as some can influence LFT results.
- The Blood Draw: The test itself involves a simple blood draw. A nurse or phlebotomist will clean an area on your arm, usually the inside of your elbow, and insert a small needle into a vein to collect a sample of blood. The process is very quick, typically lasting only a few minutes, with minimal discomfort.
- Is it a Single-Day Thing? Yes, the test is performed in a single, short visit to a clinic or laboratory. You can resume your normal activities immediately afterward unless your doctor advises otherwise.
Step 4: Receive Your Results
Results from your liver function test are typically available within a few days and will be sent directly to your doctor for review. Your report will show the levels of each marker alongside the normal range of a liver function test for comparison.
It is crucial to understand that an “abnormal” result—one that falls outside the normal range of a liver function test —does not automatically mean you have a serious liver condition. Factors like age, gender, diet, and even strenuous exercise can influence your results. A doctor will interpret your numbers in the context of your overall health, symptoms, and medical history to determine their significance.
Step 5: What Happens After Your LFT Results?
Once your LFT results are available, your doctor will review them with you and explain what they mean for your health.
- If Results are Normal: This is reassuring and suggests your liver is likely functioning well. Your doctor may recommend routine monitoring depending on your overall health profile.
- If Results are Abnormal: Your doctor will discuss the potential reasons. A single abnormal result may sometimes be temporary, and a repeat test might be ordered. If the results are significantly abnormal or persistently elevated, further investigation is usually required to identify the underlying cause. This may include additional blood tests, imaging studies like an ultrasound or CT scan, or a consultation with a liver specialist.
When further investigation is needed, seeking expert guidance is crucial. For comprehensive liver treatment in Singapore, consulting a specialist ensures you receive a definitive diagnosis and a clear path forward.
Schedule a Liver Function Test with Dr. Thng
Your liver health is too important for uncertainty. A liver function test is a simple yet powerful tool for understanding, monitoring, and protecting your liver health. Whether used for routine screening or to investigate specific symptoms, it provides invaluable information that empowers you and your doctor to make informed decisions.
If you have been advised to get a liver function test in Singapore, or if you have concerns about your liver health, it is best to consult a healthcare professional or a specialist. If you are looking for a liver surgeon in Singapore, Dr. Thng Yongxian is a highly experienced hepatobiliary and pancreas surgeon dedicated to providing expert diagnosis and personalised care for liver conditions.
To find out more about liver function tests with Dr. Thng, please contact our clinic or visit our service page here.