What is the liver?
The liver is an organ that sits in the upper part of your stomach and is essential for your health. It plays a role in over 500 functions in your body. These include:
- creating bile acids — helps you digest food
- breaking down and storing nutrients
- detoxifying your blood
- fighting infections
- helping your blood to clot
- maintaining hormone balances
- regulating blood sugar levels
Where is your liver?
The liver is the second largest organ in your body. It sits in the upper part of your stomach, on the right side of your abdomen.
What is a liver blood test?
A liver blood test was formerly known as a liver function test or LFT. The name has changed to reflect new guidance from the British Liver Trust published in 2022, reporting that a liver blood test can’t diagnose or rule out liver disease when analysed on its own.
This means your liver blood test results might be normal even if you have liver disease. But it’s important to note that many people with abnormal liver blood test results don't have liver disease.
What can a liver blood test tell you?
A liver blood test measures the levels of various things in your blood, like proteins, liver enzymes, and bilirubin. This can help check the health of your liver and for signs of inflammation or damage.
Your liver can be affected by:
- liver infections — like hepatitis B and hepatitis C
- non-alcoholic fatty liver disease
- alcohol-related liver disease
- scarring on your liver (cirrhosis)
- gallbladder disease
- possible side effects of medications and herbal remedies — like St John’s Wort
- haemochromatosis — when your body stores too much iron
- autoimmune conditions — when your body reacts and attacks itself
Who should do a liver blood test?
A liver blood test might be helpful if you:
- have symptoms of fatigue and nausea
- drink more than 14 units of alcohol a week
- are worried about fatty liver disease
- are overweight
- have type 2 diabetes
- have raised cholesterol
- have a genetic disease — like haemochromatosis
- are taking medications which affect your liver
When doing this blood test, one of our reporting GPs will review your:
- previous liver blood test results (if you have any)
- health profile
- body mass index (BMI)
- alcohol consumption
What’s included in a liver blood test?
The main proteins measured in a liver blood test are:
- albumin — helps transport nutrients and hormones, as well as helps grow and repair tissues in your body
- globulin — helps your blood clot and fights infections
- total protein — this is your albumin and globulin levels combined
The main enzymes measured in a liver blood test are:
- alkaline phosphatase (ALP) — helps break down proteins so your body can absorb them
- alanine transferase (ALT) — also helps break down proteins
- gamma-glutamyl transpeptidase (GGT) — helps detoxify drugs and alcohol
Bilirubin is a yellow pigment. When your red blood cells break down, bilirubin is what’s leftover. It’s a waste product with no known function in your body.
What are the signs and symptoms of liver disorders?
The signs and symptoms of a liver disorder might include:
- tiredness and fatigue
- loss of appetite
- weight loss
- low sex drive (libido)
- jaundice — when you have too much bilirubin, it causes yellow skin and eyes, and itchy skin
- nausea and vomiting
- abnormal bruising and bleeding
- abdominal pain
- a build-up of fluid in your abdomen
You must see your doctor and check your liver health if you have these symptoms.
How do you check your liver health?
You can check your liver health by using a liver blood test in the comfort of your own home.
Regularly checking your liver health is particularly beneficial if you:
- drink a lot of alcohol — it’s best to drink no more than 14 units a week (roughly 6 pints of beer or 6 medium glasses of wine)
- carry excess weight, or you’re obese
- have diabetes
- have high blood pressure
- have high triglyceride levels (fats in your blood)
- have haemochromatosis — a build-up of iron in your body
If your liver blood test results are out of range, your doctor might do an ultrasound scan or biopsy to check for liver damage.
What if your liver blood test results contain abnormalities?
Mild to moderate abnormalities in your liver blood test results are commonly associated with:
- non-alcoholic fatty liver disease
- alcohol-related liver disease — for example, you might have elevated gamma-glutamyl transpeptidase (GGT) levels
- certain medication — like some antibiotics, anti-epileptic drugs, and non-steroidal anti-inflammatory drugs (NSAIDs) like ibuprofen
- infections like hepatitis B and C
If your liver blood test results are abnormal, we recommend following them up with a healthcare professional. They will investigate your results further to help rule out or diagnose liver disease.
The National Institute for Health and Care Excellence (NICE) recommends a FibroScan if you drink more than 50 units of alcohol a week for men or 35 units or more a week for women.
A FibroScan is a non-invasive medical device that checks for liver fibrosis and cirrhosis (scarring) by measuring how stiff your liver is.
Interpreting your liver blood test results
Since a liver blood test measures many different health markers, it can help pick up many issues. High or low levels of specific proteins and enzymes can indicate a problem with your liver.
If your liver or kidneys aren’t working properly, it can cause your albumin levels to drop. This might be caused by a poor diet, an infection, kidney disease, or inflammation.
Normal albumin levels range from 35-50 g/L.
Many conditions can cause your globulin levels to increase or decrease.
Low protein, globulin, and albumin levels might suggest:
- liver disease
- kidney disease
- malnutrition or malabsorption
High globulin, protein, and albumin levels could indicate:
- an infection
There’s a phenomenon in cirrhosis when your albumin levels are low, and your globulin is high.
Normal globulin levels range from 19-35 g/L.
Total protein (albumin and globulin)
Low total protein levels can signify a liver or kidney disorder. It might also signify that you’re not absorbing food properly, like in inflammatory bowel disease (IBD) or coeliac disease.
High total protein levels can signify dehydration, chronic inflammation or an infection like viral hepatitis. It’s rare, but it can also be a sign of a bone marrow disorder or HIV.
If you have cirrhosis, your total protein levels might be normal — this is because globulin rises as albumin levels fall.
Normal total protein levels range from 63-87 g/L.
Alkaline phosphatase (ALP)
High ALP levels can signify liver inflammation, damage to your gallbladder, or bone disease. Raised levels can also happen during puberty and pregnancy.
An ALP level under 130 IU/L is considered normal for men and women.
Alanine transferase (ALT)
ALT is mainly found in your liver, so it’s a good indicator of your liver health. A high ALT level can be a sign of liver damage. An ALT level between:
- 15-50 IU/L is considered normal for men
- 10-35 IU/L is considered normal for women
Gamma-glutamyl transpeptidase (GGT)
High GGT levels can be a sign of liver damage or disease. If you drink large amounts of alcohol for a long period of time, your GGT levels usually increase.
A GGT level:
- under 71 IU/L is considered normal for men
- under 42 IU/L is considered normal for women
High bilirubin levels can be a sign that your liver is damaged. If you drink excessive amounts of alcohol, take certain medications, or if you’re destroying more red blood cells than usual (haemolysis), it can increase your levels. Sometimes it might be caused by Gilbert’s syndrome — a harmless inherited disorder.
A bilirubin level:
- under 24 umol/L is considered normal for men
- under 15 umol/L is considered normal for women
What affects your liver health?
How alcohol affects your liver
Drinking too much alcohol can lead to alcohol-related fatty liver disease (ARLD). This is because alcohol can increase the levels of fats in your liver. Research suggests this might result from waste products in alcohol that cause your liver to make more fatty acids.
If you stop drinking alcohol or lower your intake to a safe level, your liver usually repairs itself. If you keep drinking a lot, your liver will become inflamed. And over a few years, this can cause permanent scarring on your liver (cirrhosis) and can lead to liver failure.
How weight affects your liver
Being overweight or obese can also cause fatty liver disease, called nonalcoholic fatty liver disease (NAFLD). Other risk factors for NAFLD include:
Like with ARLD, NAFLD can cause permanent damage to your liver if left untreated for years.
How do drugs affect your liver?
Some common drugs, like acetaminophen (paracetamol) and nonsteroidal anti-inflammatories (aspirin and ibuprofen), can cause serious damage to your liver. This can happen if you take too much of it in one go or take high doses over a longer period.
Avoid using these drugs to treat your hangover symptoms until all the alcohol is out of your system. It takes your body approximately 1 hour to clear one unit of alcohol. They interfere with your liver and can cause severe side effects, even death.
Other drugs that can affect your liver include:
- steroids — a type of anti-inflammatory medicine used to treat various conditions
- antibiotics — used to treat or prevent some types of bacterial infection
- statins — used to help lower the level of low-density lipoprotein (LDL) cholesterol in your blood
- antifungal drugs — used to treat fungal infections that commonly affect your skin, hair, and nails
- antiviral drugs — used to help your body fight off harmful viruses
It’s important to always consult with your doctor when taking any medication. If a possible side effect of the medication is liver damage, you should do regular liver blood tests.
How diet affects your liver
Your diet has a significant effect on your liver health. The worst foods for your liver include:
- saturated and trans fats — like fried foods, red meat, cakes, pastries, and cream
- refined carbohydrates — like white bread and white pasta
- added sugars — like fruit juices, fizzy drinks, and sweets
- salt — like frozen foods, salted nuts, and smoked or cured meats
How to improve your liver health
The good news is that it usually takes years for permanent liver damage to develop. So if you catch it early enough, you can make many lifestyle changes so your liver can repair itself.
To improve your liver health and long-term health, you should:
- limit the amount of alcohol you have a week to 14 units — that’s equivalent to 6 pints of beer or 6 medium glasses of wine. If you can, it’s best to stop drinking altogether
- lose weight if you’re overweight or obese
- follow a healthy, balanced diet — like the Mediterranean diet
- make sure you get enough exercise — aim for a mix of aerobics and activities to improve your fitness
- drink some coffee — some studies have shown that caffeine can help improve your liver health
- avoid excess sugary food and sweet drinks