Your liver works quietly in the background every day. It helps process nutrients, medicines and alcohol, stores energy and makes important proteins.
A liver blood test gives you a snapshot of some of this activity. But one number rarely tells the whole story. The useful part is seeing how several markers fit together, then discussing the pattern with a qualified healthcare professional.
TL;DR:
- A liver blood test usually checks markers including ALT, AST, ALP, GGT, bilirubin and albumin.
- Raised ALT or AST may point to stress or injury affecting liver cells, but can also have other causes.
- ALP and GGT may suggest an issue involving bile flow, while ALP can also come from bone.
- Bilirubin is linked to the breakdown and removal of old red blood cells.
- Albumin gives information about a protein made by the liver and changes more slowly.
- Your lab’s own reference ranges matter. Do not compare your result with a random range online.
- Recent alcohol, medicines, supplements, illness, dehydration and hard training can affect results.
- An at-home test can help you arrive informed for your next GP appointment. It does not diagnose or replace clinical care.
What does a liver blood test show? A liver blood test measures several substances linked to liver cell stress, bile flow and protein production. Results must be read together, against the reference range printed on your report, and discussed with a qualified healthcare professional.
What does a liver blood test check?
A liver blood test is often called a liver function test, or LFT. The name is slightly misleading because not every marker measures liver function directly.
Think of the results as a car dashboard. One warning light may be caused by a loose connection, recent hard driving or a genuine fault. Your GP looks at the full dashboard, your symptoms, medicines, health history and any previous results.
Common markers include:
ALT and AST: signs of cell stress
ALT, or alanine aminotransferase, is an enzyme found mainly in liver cells. When these cells are irritated or damaged, ALT can leak into the blood.
AST, or aspartate aminotransferase, is found in the liver but also in muscles and other tissues. This means a raised AST does not automatically mean a liver problem.
Raised ALT or AST can have many possible causes, including:
- Metabolic dysfunction-associated steatotic liver disease, also known as MASLD
- Alcohol-related liver disease
- Viral hepatitis
- Some medicines or supplements
- Autoimmune liver conditions
- Recent strenuous exercise or muscle injury
The Specialist Pharmacy Service explains how ALT and AST are interpreted alongside other liver blood tests. It also notes that results can sometimes be abnormal without liver disease, or normal even when liver disease is present.
That is why a single raised result is not a diagnosis. Your clinician may repeat the test or arrange further checks.
ALP and GGT: clues about bile flow
ALP, or alkaline phosphatase, is linked to the bile ducts in the liver. It is also found in bone, so an isolated raised ALP does not always point to the liver.
GGT, or gamma-glutamyl transferase, is more closely linked to the liver and bile ducts. Alcohol and some medicines can affect it.
When ALP and GGT are both raised, a clinician may look more closely at bile flow or the gallbladder. Gallstones can sometimes block a bile duct. Read the NHS guide to gallstones for symptoms and when urgent help is needed.
When ALP is raised but GGT is not, your clinician may consider causes outside the liver, including bone-related causes.
Bilirubin: the yellow pigment in your blood
Bilirubin is produced when old red blood cells are broken down. Your liver processes it and sends it out in bile.
A raised bilirubin result can happen for different reasons. These may include:
- A harmless inherited pattern such as Gilbert’s syndrome
- Problems processing bilirubin
- Reduced bile flow
- Liver inflammation
- Faster-than-usual breakdown of red blood cells
If bilirubin builds up, your skin or the whites of your eyes may look yellow. This is called jaundice. The NHS advises seeking urgent medical help if your skin or the whites of your eyes turn yellow, particularly if you also notice dark urine, pale stools or itchy skin.
Albumin: a protein made by the liver
Albumin is a protein made by the liver. It helps carry substances around your blood and supports fluid balance.
Albumin changes more slowly than enzymes such as ALT. A low result can be linked to long-term liver problems, but it can also be affected by nutrition, inflammation, kidney conditions or protein loss through the gut.
It is best understood as part of the wider picture. It is not a score of how well you are eating or proof of a liver condition on its own.
Total protein and globulin
Some broader panels also include total protein and globulin.
Total protein combines albumin and globulin. Globulins are a group of proteins involved in immune activity and transport.
These markers can add context, but they are not liver-specific. Your GP will consider them alongside your full blood count, symptoms and medical history.
What can affect liver blood test results?
Your results can be influenced by more than liver disease. Before testing, record anything that may help a clinician understand the result.
Important factors include:
- Alcohol: Recent intake can affect GGT and other markers.
- Medicines: Prescription medicines, painkillers and some antibiotics can influence liver blood tests.
- Supplements: Herbal products and high-dose supplements are not automatically harmless. Tell your GP what you take.
- Illness: A recent infection can temporarily alter blood results.
- Exercise: Hard training may affect AST and other muscle-related markers. This matters if you are an athlete or regular lifter.
- Hydration: Dehydration can make collecting a finger-prick sample harder and may affect some blood measurements.
- Food and timing: Follow the instructions for your specific panel. Some tests require fasting.
- Sample collection: A difficult or delayed sample may affect quality.
Do not stop prescribed medicine to “clean up” your results. Ask your GP or pharmacist if you are unsure.
For an at-home sample, follow the official Vitall Check sampling guide. Warm your hands, drink water as instructed, avoid heavy exercise beforehand and post the sample on the same day. Some people find finger-prick collection straightforward. Others need more time or a second attempt. That is normal.
What should you do if your results are outside the range?
First, check the units and the reference range printed on your report. Ranges can differ between laboratories because testing methods and equipment vary.
Next, look at the pattern rather than one result:
- ALT or AST raised more than other markers may suggest liver cell stress, although muscle and other causes are also possible.
- ALP and GGT raised together may lead a clinician to investigate bile flow.
- A bilirubin rise with otherwise different results may need a different line of enquiry.
- Low albumin with other abnormal liver markers may require further assessment.
The NHS explains that MASLD often causes no symptoms and may be found during blood tests or scans arranged for another reason. It is linked with factors such as type 2 diabetes, high blood pressure, high cholesterol and carrying excess weight around the waist.
Lifestyle factors can matter. A balanced diet, regular movement, avoiding smoking and staying within the UK alcohol guidance may support general health. The NHS states that adults should drink no more than 14 units of alcohol per week. If you are concerned about your alcohol intake or liver health, speak with your GP rather than trying to interpret the result alone.
When should you speak to a healthcare professional?
Arrange a GP appointment if:
- Your liver markers remain outside the reference range.
- You have ongoing tiredness, nausea, poor appetite or discomfort under your right ribs.
- You take medicines or supplements that may affect the liver.
- You have risk factors for MASLD, viral hepatitis or alcohol-related liver disease.
- You want help understanding several results together.
Seek urgent medical help if you develop yellow skin or eyes, severe abdominal pain, vomiting blood, black stools, marked confusion or a swollen abdomen. The NHS information on cirrhosis explains why some of these symptoms need prompt attention.
A liver blood test is a starting point, not the final answer. Your GP may repeat your blood test, ask about medicines and alcohol, arrange additional blood tests or request an ultrasound scan.
At-home liver blood testing with Vitall Check
Vitall Check’s Complete Health & Performance Blood Test includes a group of liver-related markers, including ALT, albumin, ALP, GGT, globulin, bilirubin and total protein.
Samples are processed by UKAS-accredited partner laboratories using NHS-grade laboratory standards. Results are delivered through a secure portal, with plain-English explanations that translate raw data into clear information about where your result sits against the stated clinical reference range.
The report is a manual for understanding your numbers. It is not a diagnosis or a replacement for your GP. Use it to prepare better questions and support an informed conversation with your clinician.
Summary: use your results as a conversation starter
Your liver blood test results may show clues about liver cell stress, bile flow or protein production. They may also be influenced by exercise, alcohol, medicines, supplements, illness or sample collection.
Read the full panel together. Check your laboratory’s reference ranges. Note anything that could affect the result. Then take your questions and results to a qualified healthcare professional.
FAQ
Q: What does a liver blood test check? A: It commonly checks ALT, AST, ALP, GGT, bilirubin and albumin. These markers provide different clues and must be interpreted together.
Q: Can exercise affect liver blood test results? A: Yes. Hard training can affect some enzymes, especially AST, because it is also found in muscle. Tell your GP about recent strenuous exercise.
Q: Is an at-home liver blood test a diagnosis? A: No. It provides laboratory results and plain-English context. A qualified healthcare professional must assess symptoms, history and any follow-up tests.
Author: Vitall Check Editorial Team
The Vitall Check Editorial Team is dedicated to empowering individuals with evidence-based health information and clear, actionable insights. Every article is researched using peer-reviewed journals and official health resources, reflecting our commitment to the same high standards of accuracy as our laboratory testing services. Our goal is to make proactive wellness accessible, data-driven, and transparent.
Disclaimer: Vitall Check is not CQC registered. The content provided is for general information only, does not provide a diagnosis, and does not replace advice from a qualified healthcare professional. Our services do not include treatment, prescription, or medical advice that falls under CQC-regulated activities. Always consult with your GP or a qualified clinician before making significant changes to your healthcare regimen.
