A liver function test is a blood test that measures enzymes such as ALT, AST and ALP, along with other substances such as bilirubin and albumin, to show whether the liver is inflamed, damaged or not working well [1]. A raised enzyme level does not always mean serious disease. It may be linked to fatty liver, medications, alcohol or viral hepatitis, and it usually needs a doctor's interpretation and further tests to find the cause.
Many people are alarmed when they see an arrow or a red flag next to ALT or AST on a routine test report, and worry starts before they understand what the numbers mean. The reassuring news is that an abnormal result is not a diagnosis in itself, but it is a signal that deserves organized follow-up. In this article we explain what each number means, the most common causes of a raised result, and when it becomes a reason for concern.
What Is a Liver Function Test and What Does It Measure?
It is also known as the "liver panel". It relies on a blood sample that measures several substances the liver produces or processes [1]. The liver is the largest internal organ in the body, and it helps digest food, store energy and remove toxins [2]. You can read more about the main functions of the liver in the human body.
The most common components of this test are:
- Albumin: a protein produced by the liver [1].
- Total Protein: includes albumin and globulins [1].
- ALP, ALT, AST and GGT enzymes: enzymes that the liver produces the majority of [1].
- Bilirubin: a substance produced when old red blood cells break down, most of which the liver removes from the body [1].
- LDH: an enzyme found in most body tissues, with large amounts in the liver [1].
- Prothrombin time (PT): measures how long it takes for blood to clot, and prothrombin is a protein produced by the liver [1].
Some of these tests show how well the liver is working, while others reveal whether it has been damaged by a disease or injury. On their own, however, they usually do not diagnose a specific disease [1]. You can find a quick overview of the terms on the page Liver Function Tests (LFT).
Why Does a Doctor Order This Test and Who Needs It?
The test is used for several purposes, the most important of which are [1]:
- Determining whether liver disease or liver damage explains certain symptoms.
- Assessing how severe a disease is after it has been diagnosed.
- Monitoring a disease over time and checking how well treatment is working.
- Watching for side effects of medications that may affect the liver.
Many of these components are part of a common blood test called the comprehensive metabolic panel (CMP), so results may appear on a routine check-up even if you have no complaints [1].
Symptoms That Warrant Testing
A doctor may order the test if symptoms appear such as nausea and vomiting, loss of appetite, tiredness and weakness, yellowing of the skin and eyes (jaundice), swelling or pain in the abdomen, swelling of the ankles and legs, dark urine or pale stools, and recurrent itching [1].
Who Is Most at Risk?
Testing may be recommended even without symptoms for people at high risk of liver damage, such as those with a family history of liver disease, alcohol use disorder, obesity or diabetes, those taking medications that may harm the liver, or those who have had or been exposed to hepatitis [1].
How Do I Prepare for a Liver Function Test and What Happens During It?
A healthcare worker draws a blood sample from a vein in the arm using a small needle, and the procedure usually takes less than five minutes [1]. You may feel a slight prick, and some mild pain or a bruise may appear at the needle site, but most of these symptoms go away quickly [1].
Your doctor will tell you how to prepare. Fasting for 10 to 12 hours before the test is often required [1]. Tell your doctor about all the medications you take, as some of them can change the results, and do not stop any medication unless you are told to do so [1].
What Does a Raised ALT, AST or ALP Mean?
A doctor does not read a single number in isolation. They compare the results of all the measured substances to look for a particular "pattern" that suggests the type of problem [1]. The following table summarizes the general idea, but it does not replace the doctor's interpretation:
| Test | What is it? | What an imbalance may suggest |
|---|---|---|
| ALT | An enzyme produced mainly by the liver [1] | Hepatitis (liver inflammation) or damage to liver cells, which the doctor reads alongside the other results [1] |
| AST | An enzyme produced mainly by the liver [1] | A pattern related to the liver when read together with ALT, but not sufficient on its own for diagnosis |
| ALP | An enzyme produced mainly by the liver [1] | A problem with the liver or bile ducts, and it may also rise in bone diseases [1] |
| GGT | An enzyme produced mainly by the liver [1] | Used together with other tests to identify the source of the elevation |
The bile ducts are the tubes that carry bile, a digestive fluid produced by the liver, from the liver to outside it [1]. Taken together, the results may show that the liver is inflamed, that the inflammation is caused by alcohol, an infection or another cause, that there is a problem in the bile ducts, or that a medication is harming the liver and to what extent [1].
Bilirubin and Albumin: What Do They Tell Us About the Liver?
Enzymes generally point to inflammation or damage, whereas bilirubin, albumin and clotting time help assess the liver's actual "function".
- Bilirubin: the liver removes most of it from the body [1]. If it builds up in the blood, jaundice appears, meaning yellowing of the skin and eyes [1]. Some inherited conditions raise bilirubin, such as Gilbert syndrome, so interpretation needs a doctor [2].
- Albumin: a protein produced by the liver [1]. A low level may indicate that the liver is not working well, but other diseases can also lower it.
- Prothrombin time (PT): shows how quickly the blood clots, and prothrombin is made in the liver [1].
Taken together, the results can show how impaired the liver is if it is not working well [1]. For this reason, raised enzymes combined with abnormal bilirubin, albumin or clotting are more significant than a slight rise in a single enzyme.
What Are the Common Causes of Raised Liver Enzymes?
Liver diseases vary. Some are caused by viruses, some by medications, toxins or excessive alcohol, and others by tumors or inherited conditions [2]. The most common causes a doctor looks for are:
Fatty Liver
The medical reference classifies steatotic liver disease (fatty liver) among liver diseases linked to medications, toxins or alcohol [2]. Obesity and diabetes are risk factors that may warrant liver testing even without symptoms [1]. Because the disease sometimes has no symptoms [2], raised enzymes may be the first thing that draws attention. Read more about fatty liver disease.
Medications
Some medications may affect the liver, which is why the test is also used to monitor their side effects [1]. Tell your doctor or pharmacist about every medication, supplement and herb you take, and do not stop any prescribed medication on your own, as the decision to adjust or stop it rests with your doctor alone [1].
Alcohol
Excessive alcohol consumption is a well-known cause of liver damage [2], and alcohol use disorder is a risk factor [1]. If you drink alcohol, being open with your doctor helps them interpret your results accurately. They are there to help you, not to judge you.
Viral Hepatitis
Viruses cause several types of hepatitis, including types A, B and C [2]. You can read the details on hepatitis B and hepatitis C. Symptoms may sometimes be absent [2], so testing helps detect the condition early.
Other Causes
Inherited causes include hemochromatosis (iron overload) and Wilson's disease [2]. For more on iron, see the article on high iron stores. Some enzymes may also rise during a temporary illness; if you have been unwell recently, some results may be temporary, and the doctor may repeat the test later [1].
Does a Raised Enzyme Level Always Mean Liver Disease?
No. Abnormal results do not always mean there is a liver problem, as other conditions can also raise or lower some of the measured substances. For example, a raised ALP may indicate a bone disease or a liver disease [1]. For this reason, the doctor considers your symptoms, medical history, risk factors and the medications you take [1].
Conversely, a normal test does not rule out every liver disease, and a single result does not replace follow-up if you have symptoms or risk factors. Understanding test results is often complex, and it is best for your doctor to explain them to you [1].
When to Worry: Signs That Call for a Doctor's Visit or Emergency Care
See a Doctor Soon If
- Your test result is abnormal, especially if the elevation repeats or is accompanied by an imbalance in bilirubin or albumin.
- You develop fatigue, nausea, loss of appetite or recurrent itching [1].
- Your urine or stool changes color, or swelling appears in your ankles and legs [1].
- You notice bruises that appear easily or swelling of the abdomen [2].
- You belong to a high-risk group and want preventive testing [1].
Go to the Emergency Room or Call 911 If
- Yellowing of the skin and eyes appears along with severe abdominal pain or fever.
- You vomit blood or pass black stools.
- You experience confusion, severe drowsiness, difficulty waking up or a sudden change in consciousness.
- Your abdomen swells rapidly with shortness of breath.
Do not wait for a routine appointment if these signs appear, as they require urgent assessment at the nearest emergency department.
What Comes After an Abnormal Result?
If results are abnormal, you will usually need further tests to determine the exact cause [1]. Diagnostic tests mentioned include ultrasound imaging, CT scans and MRI, liver stiffness measurement (elastography), tests such as GGT and LDH, and in some cases a liver biopsy [2]. Not everyone needs all of these tests, and your doctor decides what suits your condition.
Once the doctor confirms a specific disease, the liver function test is later used to monitor the disease and assess how well treatment is working [1]. If some chronic conditions are left unmonitored, they may progress to liver cirrhosis. Reading about comprehensive urinalysis may also help you understand another test that is often ordered alongside routine tests.
Practical Steps in the First Few Days
- Keep a copy of the result and the date of the test, and take a clear photo of the lab report.
- Write down all the medications, supplements and herbs you take.
- Record any symptoms, how long they last and when they started.
- Do not stop any medication, and do not start any herbal remedy or supplement without consulting your doctor.
How Do I Find the Right Doctor to Follow Up on My Liver Results in Jordan?
The right doctor to follow up on raised liver enzymes is usually a gastroenterology and hepatology specialist, although the process may begin with a family physician or internist who refers you when needed. Browse gastroenterologists in Jordan and select your governorate to find the closest options:
What to Check in a Doctor's Profile
- The specialty and qualifications listed in the profile.
- The clinic location, working days and available contact or booking methods.
- The services the clinic offers, such as imaging or laboratory follow-up, if mentioned.
Questions to Ask at the Appointment
- What is the most likely cause of my raised enzymes, and what tests are needed next?
- Could any of my medications or supplements be affecting my liver?
- When should I repeat the liver function test, and what symptoms should prompt me to see you before the next appointment?
- Do I need changes to my diet, weight or habits, and what should be my priorities?
Bring your previous test results and your list of medications. Remember that the ClinicsJo directory presents doctor and clinic profiles to help with searching and contacting providers. It does not provide medical consultations, and it does not rank doctors by medical quality.
Frequently asked questions
Does a liver function test require fasting?
Doctors often ask for fasting for about 10 to 12 hours before the test, but instructions vary by laboratory and the tests ordered, so ask your doctor before the appointment. Tell them about all the medications you take, as they may affect the results, and do not stop any medication unless your doctor instructs you to.
Does a high liver enzyme level mean a serious disease?
Not necessarily. The elevation may be temporary after a passing illness, or linked to a medication or fatty liver, and it can sometimes indicate liver inflammation or another problem. The doctor evaluates the results together with your symptoms and medical history, and may order a repeat test or further tests to identify the cause.
What is the difference between ALT, AST and ALP?
All three are enzymes that the liver produces a large part of. ALT and AST are usually read in the context of liver inflammation or damage to its cells, while ALP may rise with bile duct problems or bone diseases. One number is not enough for a diagnosis, and the doctor compares the results together.
Can medications cause raised liver enzymes?
Yes, some medications may affect the liver, which is why testing is sometimes used to monitor their side effects. Tell your doctor or pharmacist about every medication, supplement and herb you take, and do not stop a prescribed medication on your own, as the decision rests with your doctor after weighing the benefits and risks.
How often should I repeat a liver function test?
Your doctor sets the timing of the repeat based on the degree of the abnormality and the likely cause. If you have been unwell recently, results may be temporary, so the test is repeated later to confirm they have returned to normal. If new symptoms appear, such as jaundice or abdominal pain, do not wait for the appointment and see your doctor.
What liver symptoms should not be ignored?
Important warning signs include yellowing of the skin and eyes, swelling of the abdomen or legs, dark urine or pale stools, recurrent itching, severe fatigue, loss of appetite, and easy bruising. If vomiting blood, confusion or severe drowsiness occurs, go to the emergency room immediately or call 911.
Sources and references
- Liver Function Tests: MedlinePlus Medical Test — MedlinePlus — U.S. National Library of Medicine. Accessed: 2026-10-26.
- Liver Diseases | Hepatic Diseases — MedlinePlus — U.S. National Library of Medicine. Accessed: 2026-10-26.