Liver function tests, often just called an LFT or liver panel, are a routine set of blood measurements that give your provider a snapshot of how your liver is doing. You might have one because of a symptom, to keep an eye on a medication, or as part of general bloodwork. Here is what the main numbers mean and how to get tested in the Ottawa area.
What a liver panel includes
A standard liver panel measures several substances that the liver makes, processes, or releases when it is under strain:
- ALT (SGPT), an enzyme found mainly in liver cells and a sensitive marker of liver-cell injury
- AST (SGOT), an enzyme found in the liver but also in muscle and heart
- ALP (alkaline phosphatase), an enzyme linked to the liver's bile ducts and to bone
- Bilirubin, a waste product from the breakdown of red blood cells that the liver clears
- Albumin, the main protein the liver makes, reflecting its manufacturing function
Some panels also include total protein and GGT, and the exact mix depends on what your provider is looking for. Together these markers show different aspects of liver health: cell injury, bile flow, and how well the liver is doing its everyday manufacturing work. You can see how a liver panel sits alongside other bloodwork in our test directory.
Why your provider might order one
- Monitoring medications that can affect the liver, such as certain long-term prescriptions
- Investigating symptoms like jaundice, abdominal pain, nausea, or unexplained fatigue
- Screening when there are risk factors, such as alcohol use, hepatitis, or fatty liver
- Following a known liver condition over time
Because the liver processes so much of what passes through the body, these tests are among the more commonly ordered in routine bloodwork. They are also frequently repeated over time, since a single set of results is most useful when your provider can compare it to earlier samples and watch for a trend rather than reacting to one reading.
Making sense of your numbers
It is tempting to read each value on its own as normal or abnormal, but liver results are best understood as a pattern. The relationship between ALT and AST, whether ALP is raised with or without bilirubin, and how albumin looks all help point toward a cause. Mildly elevated enzymes are common and often harmless, and can follow exercise, a fatty meal, or a temporary illness. It is also worth knowing that reference ranges differ slightly from lab to lab, and that a result flagged as outside the range is not automatically a problem. Only your provider can interpret your specific results in light of your history, so treat any single number as one piece of a bigger picture rather than a diagnosis.
Do you need to fast?
Liver panels do not always require fasting, but your provider sometimes requests it, often because the liver test is bundled with glucose or a lipid panel that does. Your requisition will indicate whether fasting is needed. If it is, water is fine but avoid food, coffee, tea, and gum beforehand; our prepare-for-a-blood-test guide walks through the details.
Where to get liver testing in Ottawa
Liver function testing is a standard blood draw available at every Bio-Test Laboratory location across Ottawa-Carleton and Eastern Ontario. Walk in with your Ontario health card and requisition, with no appointment needed for routine bloodwork, or book ahead through the patient portal. OHIP covers medically necessary liver testing. Mornings are busiest with fasting patients, so plan accordingly, and find your nearest of our 11 locations. Home visits are available by request if travelling to the lab is difficult.