Liver test: when to get tested and how to do it correctly

The liver is a «silent» laboratory of the human body. It performs over 500 functions: it neutralizes toxins, regulates glucose levels, synthesizes proteins, bile, and hormones. But at the same time, it is practically painless, even when it is already seriously damaged. That is why laboratory testing of the liver is one of the most reliable ways to prevent complications.

Key markers of liver function

Liver tests usually include a set of tests known as «liver function tests.» They cannot be evaluated in isolation—it is important to consider the entire context:

• ALT (alanine aminotransferase): an enzyme released when liver cells are destroyed. The most sensitive indicator of hepatocellular damage.

• AST (aspartate aminotransferase): an enzyme also found in the heart and muscles. Its elevation, together with ALT, is a signal of an acute process in the liver.

• Bilirubin (general, direct, indirect): a pigment formed when red blood cells break down. High levels are a sign of impaired bile flow or liver failure.

• GHT (gamma-glutamyltransferase): increases with alcohol abuse or cholestasis.

• Alkaline phosphatase (ALP): increases with damage to the bile ducts.

• Albumin: the main protein synthesized in the liver. Its decrease is a sign of chronic dysfunction.

• Prothrombin time (PT) or INR (international normalized ratio): indicates the liver's ability to synthesize clotting factors.

Lesser known but valuable methods

In addition to standard tests, modern hepatology also uses other tests:

• Fibrotest — biochemical assessment of the degree of fibrosis without biopsy.

• Elastography (e.g. FibroScan) is an ultrasound method for measuring the stiffness of liver tissue.

• Antibodies to hepatitis B and C — markers of infectious liver damage.

• Ceruloplasmin і copper in serum — if Wilson's disease is suspected.

• Autoantibodies — if autoimmune hepatitis or primary biliary cholangitis is suspected.

How to prepare for the analysis

To ensure reliable results, follow these simple rules:

• Donate blood on an empty stomach (at least 8 hours without eating).

• The day before the test, do not consume alcohol, fatty and fried foods.

• If possible, stop taking medications that may affect the liver (but only after consulting with your doctor).

• It is not recommended to perform intense physical activity the day before.

When to check your liver

• If you have increased fatigue, nausea, yellowing of the skin or eyes

• After the transfer viral hepatitis

• With prolonged use of medications (antibiotics, anticonvulsants, hormones)

• If you you regularly drink alcohol

• With obesity, metabolic syndrome or diabetes

• As screening in case of suspected chronic liver damage

Difficult diagnosis without symptoms

Liver diseases often go unnoticed until they reach the stage of cirrhosis or hepatocellular carcinoma. According to European Association for the Study of the Liver (EASL), up to 70% cases of cirrhosis are diagnosed at later stages, when liver function can no longer be fully restored. That is why preventive diagnostics play a critically important role.

The best strategy is not to wait for symptoms, but to periodically undergo a basic examination, especially if there are risk factors. The liver is capable of regeneration, but only if the problem is detected in time. Do not postpone the analysis - liver health can save your life.