Liver Blood Test

Yes. This test is available as a finger-prick kit posted to your home: a few drops of blood from a fingertip, posted back in the prepaid envelope, analysed in an accredited laboratory for the same six liver markers a GP would order, with a GP report explaining the result. It is the same measurement as the clinic test. If you would rather have the sample taken for you, book a Goodbody clinic or a nurse home visit. No fasting or preparation is needed.

A liver function test, LFT or liver profile, measures enzymes and proteins in the blood that change when liver cells are stressed, inflamed or damaged. ALT leaks from liver cells when they are injured. Gamma GT rises with alcohol, fatty liver and bile duct problems. ALP rises with bile duct blockage and some bone conditions. Bilirubin, the pigment cleared by the liver, rises when it cannot keep up, and causes jaundice. Albumin and total protein show whether the liver is making proteins properly, which falls only when damage is advanced. Together they show whether the liver is under strain, roughly why, and how seriously.

Fatty liver, now called metabolic dysfunction-associated steatotic liver disease, is the most common liver condition in the UK, and it usually causes no symptoms. On a blood test it most often shows as a mildly raised ALT and gamma GT, sometimes with raised triglycerides and HbA1c on other tests. Normal liver enzymes do not fully exclude it, which is why a GP may add an ultrasound or a fibrosis score if you are overweight or have diabetes. If your ALT or GGT is raised and you drink little, fatty liver is the most likely explanation, and it is reversible with weight loss.

Yes, and it is the most common reason people take this test. Gamma GT is the enzyme most sensitive to alcohol and rises with sustained heavy drinking; ALT and bilirubin rise as strain increases; a falling albumin signals long-term damage. A normal result after a period of heavy drinking is reassuring but does not mean no harm has been done, because the liver can compensate for a long time. Retesting after a month or more of cutting down shows how quickly gamma GT and ALT recover, which most people find motivating.

At least 72 hours after your last heavy session, so the result shows your baseline rather than the immediate effect of a binge; gamma GT in particular stays raised for two to three days. If you want to know what regular drinking is doing to your liver, do not abstain for longer than usual before the test, or you will measure your best week rather than your typical one. If you are testing to see whether a period of cutting down has helped, three to four weeks of reduced drinking is long enough to see gamma GT fall.

Paracetamol at normal doses does not usually change liver enzymes, but regular use at the top of the recommended dose, or combining it with alcohol, can raise ALT; an overdose causes severe liver injury. Many other common medicines raise liver enzymes: statins, some antibiotics, antifungals, antiepileptics, methotrexate and some herbal supplements. A raised result in someone taking one of these medicines usually means monitoring rather than stopping, and is worth raising with whoever prescribes it.

It depends which marker and by how much. A mildly raised ALT or gamma GT, up to two or three times the upper limit, is most often fatty liver, alcohol or medication, and is usually repeated in a few months after addressing the likely cause. Raised ALP with raised bilirubin points to the bile ducts and needs GP assessment sooner. Very high ALT, into the hundreds, suggests acute hepatitis and needs prompt medical attention. Borderline results, just above the range, are common, often normal on repeat, and your GP report will explain whether to act now or retest.

Because liver enzymes fluctuate day to day and a single mildly abnormal result often normalises. GPs repeat a borderline liver test after one to three months to see whether it was a blip or a trend, usually after you have cut down on alcohol, lost some weight or changed a medication. A persistently raised result is what triggers further investigation, such as a hepatitis screen, an iron test, an autoimmune screen or an ultrasound. This test at £49 makes repeating it easy.

Ranges vary slightly by laboratory and are printed beside each result on your report. As a guide, ALT is usually below about 40 to 50 U/L, gamma GT below about 55 to 70 U/L, ALP 30 to 130 U/L, bilirubin below 21 micromol/L, and albumin 35 to 50 g/L. Men and people who are heavier tend to sit higher in the range. Your GP report interprets each marker against the laboratory's own range, so you do not need to look anything up.

The liver has no pain nerves and enormous reserve, so early damage causes no symptoms at all, which is why blood testing matters. When signs appear they include persistent tiredness, nausea or loss of appetite, pain or fullness under the right ribs, itching, dark urine and pale stools, yellowing of the skin or eyes, easy bruising, swollen ankles or abdomen, and confusion. Any of these, particularly jaundice, needs a GP promptly rather than a screening test.

No. Food does not meaningfully change the six liver markers, so eat and drink normally, take your usual medication and simply avoid heavy drinking for 72 hours beforehand. If you are combining this with a cholesterol or blood sugar test, those may need fasting; our General Health test, which includes liver function with kidney, cholesterol and iron, asks for an overnight fast.

From £49 with the home finger-prick kit, £69 at one of 250+ Goodbody clinics or £89 with a nurse home visit, including laboratory analysis and a GP report. Results are emailed within 3 to 5 working days of your sample reaching the laboratory, with the report explaining each marker and what to do next. Private liver function tests in the UK typically cost £40 to £80.