Abnormal Liver Blood Tests

The liver is your largest internal organ and is divided into two lobes. It sits in the tummy (abdomen), under your diaphragm on the right-hand side and is surrounded by a strong fibrous capsule. It is usually tucked under the ribs, which protect it, although in some people the edge of the liver protrudes slightly.

To see a diagram of the anatomy of the liver click here.

If the liver is swollen, through inflammation or disease, it can swell out from under the ribs and make your tummy swollen.

Your liver is your body’s ‘factory’, carrying out hundreds of jobs that are

vital to life. This includes manufacturing (e.g., making proteins, hormones and blood clotting factors), storage (e.g., sugars, vitamins and minerals) and detoxification (e.g., breaking down drugs, alcohol and poisons). It is very tough and able to continue to function when most of it is damaged. It can also repair itself, even renewing large sections.

In total, the liver has around 500 different functions. Importantly it:

• fights infections and disease

• destroys and deals with poisons and drugs

• filters and cleans the blood

• controls levels of cholesterol

• produces and maintains the balance of hormones

• produces enzymes and other proteins

• is responsible for many chemical reactions in the body, such as blood clotting and tissue repair

• processes food once it has been digested

• produces bile to help break down food in the gut

• stores energy that can be used rapidly when the body needs it most

• stores sugars, vitamins and minerals, including iron

• repairs damage and renews itself.

Your liver responds to harm by becoming inflamed. Any inflammation of the liver is known as hepatitis, whatever its cause. Sudden inflammation of the liver is known as acute hepatitis. When inflammation of the liver lasts longer than six months, it is known as chronic hepatitis.

Inflammation is part of the process of repairing damaged tissue. In a similar way to a scab forming over a skin wound, a temporary fibrous ‘scaffold’ forms while new liver cells regenerate.

If your liver is repeatedly harmed, new liver cells cannot regenerate fast enough, and the fibrous scaffold remains as a scar. This is called fibrosis and can take a variable amount of time to develop. When fibrosis is present, your liver may be able to keep functioning quite well.

Removing or treating the cause of the inflammation may reverse some, or all, of the fibrosis and prevent further liver damage.

If the harm to your liver continues, the inflammation and fibrosis can spread throughout your liver, changing its shape and affecting how well your liver cells work. This is known as compensated cirrhosis. Even at this stage, people can have no obvious signs or symptoms.

The scar tissue in cirrhosis interrupts the blood flow through the liver. As a result, the blood pressure in the veins in your abdomen is increased and may result in bleeding.

Scar tissue in cirrhosis is difficult to remove and may be permanent. However, further progression can be halted and your cirrhosis stabilised, if the cause of the liver damage is removed.

Cirrhosis increases your risk of liver cancer and can lead to liver failure.

If damage to your liver continues, it will become unable to function sufficiently (decompensated cirrhosis) and start to fail; this is sometimes referred to as ‘end-stage liver disease’. At this stage chemicals and waste products can build up in the body, commonly causing jaundice, ascites (a build-up of fluid in the abdomen) and hepatic encephalopathy (confusion and memory loss).

In the final stages of liver disease, the build-up of waste products may lead to multiple organ failure and loss of life.

A liver blood test looks at the chemicals (enzymes), proteins and other substances made by the liver to assess whether levels of any of these are abnormal.

These tests are often taken routinely by your GP, Practice Nurse, Phlebotomist or Health Care Assistant as part of the monitoring process of chronic diseases such as diabetes, ischaemic heart disease, high blood pressure etc. They may be part of a series of blood tests used to screen for health problems rather than specifically because of concerns about liver disease (full blood count, kidney function tests, blood sugar and thyroid function tests also fall into this category).

It is therefore not unusual to identify “abnormal” liver blood test results coincidentally after having routine blood tests for something else.

“Abnormal” liver blood test results are defined as any result that falls outside of the “normal range”.

Normal Range

The ‘normal range’ is a range of values given by the local laboratory for liver blood tests. The range varies slightly between laboratories according to the measurement methods that they use.

The ‘normal’ limits are defined by laboratories as the range of levels inside which 19 of every 20 people with healthy livers will fall. This means that, for any one liver test, around 1 in 20 people (5%) with healthy livers will have a result that is slightly abnormal. There will, in most cases, be nothing wrong with their liver; having a test result that’s just outside of the normal range when there are only one or two slight abnormalities out of the whole range of tests usually has no clinical significance.

Abnormal Liver Blood Test Results

Abnormal liver blood test results are relatively common and most people with these results have normal livers. An infection or a reaction to medication might affect your blood test results and sometimes a repeat liver blood test is all that’s needed.

Liver blood tests are not a diagnosis; they are a set of clues which help doctors make a diagnosis.

For most liver blood tests, a result that is less than twice the upper limit of the normal value is regarded as slightly abnormal whereas a result that is greater than twice the upper limit of the normal value is regarded as more significant, however, these results always need to be interpreted in a clinical context (i.e., taking in to account the individual health circumstances of the patient being tested).

Sometimes an abnormal liver blood test is normal for you. If you already know this is the case, then it may be that no action is needed. A common example of this is Gilbert’s syndrome, when you have a naturally raised level of bilirubin, but other liver function tests are normal, and you are well. Your doctor will tell you if you have Gilbert’s syndrome.

The main liver blood tests are:

Alanine aminotransferase (ALT) and aspartate aminotransferase (AST)

ALT and AST are enzymes found in the liver cells (hepatocytes) which leak

into the blood stream when the liver cells are damaged. They indicate the

degree of inflammation present in the liver. Levels of ALT and AST are usually high in conditions such as hepatitis – possibly twenty to fifty times higher than normal. The ALT ‘value’, or level, is more specific to the liver than the AST value because the AST value may also be high if there is muscle damage elsewhere in the body. Monitoring levels of these enzymes can help doctors assess how much liver scarring (fibrosis) there is in conditions such as non-alcohol related fatty liver disease (NAFLD) and alcohol-related liver disease.

Alkaline phosphatase (ALP) and y-Glutamyltransferase (GGT)

These are enzymes found mainly in the bile ducts of the liver. Increases in ALP and another liver enzyme called y-Glutamyltransferase (GGT) can indicate obstructive or cholestatic liver disease, where the flow of bile from the liver is blocked because of an obstruction of the bile duct. GGT levels are also a potential indicator of how much alcohol a patient drinks and can also be higher in those with non-alcohol related fatty liver disease (NAFLD).

Bilirubin

Bilirubin is produced when red blood cells break down, and is the main pigment in bile (a yellow/green substance made by your liver that aids digestion). An increase of bilirubin causes jaundice, characterised by a yellowing of the eyes and skin in liver disease.

Albumin

This is a protein made by the liver that makes up about 60 per cent of total protein in the blood, helping to maintain tissue growth and repair. It stops fluids from leaking out of blood vessels and carries nutrients and hormones around the body. Albumin levels may decrease if the liver is damaged.

The levels of each individual liver blood test will be given in numbers and values. The laboratory where the blood is being tested provides a ‘normal range’ against which your test results are measured (see above). An abnormal liver blood test result is defined as being below or above the normal range.

It’s important that you talk to your doctor or specialist nurse about what your test results mean, rather than compare results with other people undergoing diagnosis (via online forums, for example).

Interpretation of test results depend on the overall health of the individual, any previous test results and known co-existing disease. Each testing laboratory will produce a set of slightly different results, which is why it’s important your clinician explains them to you.

Different diseases of the liver will cause different types of damage and will affect liver blood tests accordingly.

It’s important to remember that liver blood tests can help to indicate which disease a patient may have but they can’t give an actual diagnosis.

There is a difference between what you need to do to keep your liver healthy most of the time and what you need to do if your liver is inflamed or damaged.

If you are well, the way to look after your liver is with a balanced diet with a good fibre content, exercise, maintenance of a healthy weight, avoiding ‘fad’ diets (which can challenge the kidneys and liver hard), avoiding unnecessary medicines and supplements including paracetamol, stopping smoking, and staying within the recommended limits for alcohol. The liver does not need a detox diet, which will not help it and will often (if it is very low-calorie, for instance) make it work harder. The liver is a digesting, storage and detoxing organ.

If your liver is inflamed and injured (for example, you have hepatitis and are jaundiced) or you have advanced liver disease (for example, cirrhosis) then, depending on the severity, you may be advised to have a special diet. This involves using carbohydrates as your major source of calories, eating fat moderately and cutting down on protein. You may be advised to take vitamin supplements and, if you are retaining fluid, you will be advised to reduce your salt consumption to less than 1500 milligrams per day.

Useful information about abnormal liver blood tests

• Liver disease tests explained – British Liver Trust
• Liver Blood Tests FAQs – British Liver Trust
• Abnormal Liver Function Tests – patient.info
• Liver Blood Tests – Lab Tests Online

If you have been referred for a specialist opinion your details will be reviewed and it may be recommended that you are seen by a hospital clinician. Information to support you in choosing your preferred hospital, including waiting times can be found using the links below.

How long will I wait?

If a hospital assessment and/or treatment is clinically recommended your information will be sent to a specialist. Click below to find out more about waiting times for routine hospital assessment and/or treatment.

• Waiting times
• Find services near you

Follow the links to find out more about the support available:

• British Liver Trust
• Macmillan
• Drinkaware