Liver Function (LFT) Blood Tests: Your UK Guide
Your liver works harder than almost any other organ in your body. It processes everything you eat and drink, filters toxins from your blood, produces bile for digestion, stores essential vitamins, and regulates your blood sugar levels. Despite all this, liver disease often develops silently. There are few early symptoms, and by the time you notice something is wrong, significant damage may already be done.
The good news is that a simple liver function blood test (LFT) can spot problems early, often before any symptoms appear. With almost one in three UK adults now estimated to have early-stage non-alcoholic fatty liver disease (NAFLD), regular testing has never been more important.
What a Liver Function Blood Test Measures
A standard LFT panel measures several key enzymes and proteins that tell your doctor how well your liver is working.
ALT (Alanine Aminotransferase) is an enzyme found mainly in the liver. High levels suggest liver cells are damaged or inflamed. The normal range is typically 10–40 IU/L. AST (Aspartate Aminotransferase) is another enzyme released when liver cells are damaged, often compared with ALT to help determine the cause of liver injury. ALP (Alkaline Phosphatase) is an enzyme linked to the bile ducts; high levels can suggest a blockage or bile duct problem.
GGT (Gamma-Glutamyl Transferase) is a very sensitive marker for bile duct issues and heavy alcohol use, though it can also be elevated by certain medications. Bilirubin is a waste product from the breakdown of red blood cells, and high levels cause jaundice (yellowing of the skin and eyes). Finally, the panel measures albumin, a protein made by the liver where low levels can indicate chronic liver disease or cirrhosis, plus total protein in your blood, which helps assess liver and kidney function together.
Why You Might Need a Liver Function Test
Many people assume liver problems only affect heavy drinkers, but that’s simply not true. Non-alcoholic fatty liver disease (NAFLD) is now the most common liver condition in the UK, and it’s closely linked to obesity, type 2 diabetes, and metabolic syndrome.
You should consider a liver function test if you’re overweight or have type 2 diabetes, both major risk factors for NAFLD, or if you drink alcohol regularly, since even moderate drinking can affect liver enzymes over time. Certain medications matter too: statins, paracetamol (especially in high doses), and some antibiotics can affect liver function.
Other reasons include a family history of liver disease or haemochromatosis (iron overload), persistent tiredness (fatigue is one of the most common early signs of liver stress), yellowing of the skin or eyes (a sign of elevated bilirubin that needs immediate attention), or a recent health kick, because rapid weight loss can temporarily increase liver enzymes as your liver processes stored fat.
The NHS vs. Private Liver Function Testing
Your GP can arrange an NHS liver function test if you have symptoms or risk factors, but there are some limitations. You need a referral, so you can’t just request a check-up without a clinical reason. Waiting times are long: NHS diagnostic waiting lists remain stretched, with over 1.8 million people waiting for tests as of early 2026. And repeats are limited, so if you’re monitoring a known condition, you may only get tested every 6-12 months.
Private testing gives you full control. You can order a test whenever you want, choose exactly which markers to include, and get results back in days rather than weeks.
How Much Does a Private Liver Function Test Cost?
To compare liver function test prices across all providers side by side, visit our compare page to look at liver function or metabolic health tests.
| Provider | Test | Price | Link |
|---|---|---|---|
| Medichecks | Liver Function Blood Test | £39 | View test |
| Forth | Liver Function Blood Test | £49 | View test |
| Medichecks | Core Health Blood Test (includes LFT) | £55 | View test |
| Numan | Metabolic Health Blood Test (includes LFT) | £68 | View test |
| Randox | General Health Test (includes LFT) | £84 | View test |
| Bluecrest Wellness | Blood Health Profile (includes LFT) | £85 | View test |
| Thriva | Metabolic Health Blood Test (includes LFT) | £96 | View test |
| Bluecrest Wellness | Enhanced Liver Fibrosis (ELF) | £155 | View test |
Medichecks offers the best value for a standalone liver function test at £39, while Forth is close behind at £49. If you want a broader picture of your metabolic health, Numan’s Metabolic Health test at £68 includes liver markers alongside kidney function, cholesterol, and blood sugar, which is excellent value for a comprehensive check. For advanced liver fibrosis assessment, Bluecrest Wellness offers the ELF test at £155, which is typically only available on the NHS for patients with confirmed liver disease.
Understanding Your Results
Liver function test results need to be interpreted as a whole picture, not marker by marker. Here’s a rough guide to what the patterns might mean:
Raised ALT and AST suggests liver cell damage. Common causes include NAFLD, alcohol-related liver disease, viral hepatitis, or medication side effects. Raised ALP and GGT points instead to a problem with the bile ducts: it could be gallstones, a bile duct blockage, or certain liver conditions like primary biliary cholangitis.
Raised bilirubin with otherwise normal markers is often Gilbert’s syndrome, a harmless genetic condition affecting about 5% of the UK population. It’s not a disease and doesn’t need treatment. Low albumin can indicate chronic liver disease or cirrhosis, but it can also be caused by poor nutrition or kidney problems.
A single abnormal result doesn’t necessarily mean you have liver disease. Many things can temporarily raise liver enzymes, from a recent bout of heavy drinking to a viral infection or even intense exercise. Your GP will usually recommend repeating the test in a few weeks to see if the levels have returned to normal.
What If Your Results Are Abnormal?
If your liver function test comes back with raised markers, here’s what to do:
Cut back on alcohol. If you drink regularly, try giving your liver a break. The NHS recommends no more than 14 units per week (about 6 pints of beer or 7 glasses of wine), spread across at least three days.
Lose weight if you’re overweight. Even a 5-10% reduction in body weight can significantly reduce liver fat and improve enzyme levels. The Mediterranean diet is particularly effective for liver health.
Check your medications. Some common medications can raise liver enzymes. Paracetamol at high doses, certain statins, and some antibiotics are known culprits. Don’t stop prescribed medication without speaking to your GP first.
Get tested for hepatitis. If your liver enzymes remain raised, your GP may recommend testing for hepatitis B and C, which can cause chronic liver inflammation.
Monitor regularly. If you have NAFLD or another chronic liver condition, repeat testing every 6-12 months is recommended to track changes. Private testing makes this easy, since you can order a repeat test without needing a GP appointment each time.
Header image from Pexels
Disclaimer: This article is for informational purposes only and is not a substitute for professional medical advice. Always consult a GP or qualified healthcare provider before making decisions about your health.