Abnormal liver enzyme levels – what do the lab results indicate?

Elevated liver enzyme levels often come as a surprise to patients during a routine blood test. If you have ever found that your liver function values are highlighted in your laboratory results, it is natural to feel concerned and to seek answers. It is important to know that abnormal liver enzyme levels do not always indicate a serious illness, but they certainly warrant attention.

The liver is our body’s largest internal organ, performing more than 500 different functions. When liver cells are damaged or liver function is impaired, various enzymes are released into the bloodstream, which can be detected through laboratory tests. These enzymes serve as important indicators, helping doctors to assess the condition of our liver.

In this detailed guide, you can find out what the various liver enzyme levels mean, what might be causing them, and when further tests are needed. Our aim is to provide you with clear, easy-to-understand information to help you better understand your laboratory results and know when it is advisable to see a doctor.

What do liver enzyme levels indicate?

During a liver function panel test, we measure several different enzymes and proteins, which together provide an indication of the condition of the liver. These values can be divided into two main categories: enzymes indicating liver cell damage and parameters indicating cholestasis (impaired bile flow).

Enzymes indicating liver cell damage

ALT (Alanine aminotransferase) – formerly known as SGPT

ALT is found primarily in liver cells; therefore, an elevated level is a specific indicator of liver damage. The normal range is generally between 10 and 40 U/L. When liver cells are damaged, ALT is released into the bloodstream, causing its level to rise.

AST (Aspartate aminotransferase) – formerly known as SGOT

AST is found not only in the liver, but also in the muscles, heart, kidneys and brain. Its normal range is also around 10–40 U/L. In cases of liver damage, it often rises alongside ALT.

Enzymes indicative of cholestasis

ALP (Alkaline phosphatase)

This enzyme is found in large quantities in the walls of the bile ducts. An increase in its level usually indicates a bile flow disorder. The normal range for adults is between 44 and 147 U/L.

GGT (Gamma-glutamyl transferase)

GGT is also found in the bile ducts and is particularly sensitive to the effects of alcohol. It helps to distinguish between an increase in alkaline phosphatase of hepatic origin and one of skeletal origin.

Other important parameters

Bilirubin
Bilirubin is produced by the breakdown of red blood cells and is processed by the liver. Elevated levels can cause jaundice. We measure three forms: total, direct (conjugated) and indirect (unconjugated) bilirubin.

Albumin and total protein

These indicate the liver’s ability to produce protein. A decrease in these levels may indicate chronic liver disease.

Common causes of abnormal liver enzyme levels

Viral hepatitis

Viral hepatitis is one of the most common causes of a significant rise in liver enzyme levels. The hepatitis A, B, C, D and E viruses can all cause acute or chronic hepatitis. In cases of acute viral hepatitis, ALT and AST levels often rise above 1000 U/L.

Hepatitis B and C are particularly dangerous because they can cause chronic infection, which can remain symptom-free for decades whilst gradually damaging the liver. Hepatitis A is usually acute in nature, but results in a full recovery.

Alcoholic liver disease

Chronic alcohol consumption gradually damages the liver. Typically, the AST/ALT ratio is greater than 2:1. Alcoholic liver disease progresses through three stages: fatty liver, alcoholic hepatitis and, ultimately, cirrhosis may develop.

It is important to note that even moderate alcohol consumption can cause liver damage, particularly in women, who are more sensitive to the effects of alcohol.

Drug-induced liver damage

Many medicines can cause liver damage. The most common causes include paracetamol overdose, antibiotics, painkillers and certain heart medicines. A diagnosis of drug-induced liver injury (DILI) is made when:

The AST or ALT level is more than five times the upper limit of the normal range

The ALP value is more than twice the upper limit of normal

Total bilirubin levels are above 43 µmol/L (2.5 mg/dL), accompanied by elevated enzyme levels

Non-alcoholic fatty liver disease (NAFLD)

It has become one of the most common liver diseases today, and is closely linked to obesity, diabetes and metabolic syndrome. The condition is often asymptomatic and is only detected through laboratory tests.

NAFLD may start as simple fatty liver, but in more severe cases it can progress to non-alcoholic steatohepatitis (NASH), which is associated with inflammation and can lead to cirrhosis.

Autoimmune liver diseases

Autoimmune hepatitis

In this condition, the body’s own immune system attacks the liver cells. It typically affects young women and can be diagnosed by detecting specific autoantibodies.

Primary biliary cholangitis (PBC)

This condition affects the small bile ducts and typically affects middle-aged women. Patients often complain of itching before jaundice develops.

Primary sclerosing cholangitis (PSC)

This is a rare condition that is often associated with inflammatory bowel disease. It mainly affects men and causes a gradual narrowing of the bile ducts.

Hereditary liver diseases

Wilson's disease
A rare inherited disorder that causes copper to build up in the body. It usually presents in young adulthood and can be fatal if left untreated.

Haemochromatosis

Hereditary haemochromatosis is a condition characterised by impaired iron absorption. Excess iron accumulates in the liver and causes damage to it.

Symptoms that may indicate liver disease

Early symptoms

Many liver diseases are initially asymptomatic, or cause only mild, non-specific symptoms:

Persistent tiredness and weakness

Loss of appetite

Vomiting

Discomfort or pain beneath the right rib cage

Weight loss

Later symptoms

In cases of more advanced liver disease, more characteristic symptoms may appear:

Jaundice (icterus)

The yellowish discolouration of the skin and the whites of the eyes is caused by a build-up of bilirubin. This usually becomes visible when bilirubin levels exceed 50 µmol/L.

Itch
A characteristic symptom of cholestatic liver diseases is persistent itching, which can become particularly severe at night.

Abdominal swelling (ascites)

Fluid accumulation in the abdominal cavity is the result of reduced protein production by the liver and increased portal pressure.

Skin lesions
Spider naevi, palmar erythema and yellowish skin nodules (xanthelasma) may develop.

Diagnostic tests

Laboratory tests

Basic liver function panel

ALT, AST, ALP, GGT

Total, direct and indirect bilirubin

Albumin, total protein

Prothrombin time (INR)

Additional tests to determine the aetiology

Viral hepatitis serology (HBsAg, anti-HCV, anti-HAV)

Autoimmune panel (ANA, AMA, SMA, LKM)

Iron panel (serum iron, ferritin, transferrin saturation)

Ceruloplasmin (in cases of suspected Wilson’s disease)

Alpha-1-antitrypsin level

Imaging studies

Abdominal ultrasound

The first imaging test to be chosen, which provides information on the size and structure of the liver, the condition of the bile ducts and any fluid build-up.

CT and MRI scans

They provide a more detailed picture of the condition of the liver; with their help, it is easier to assess space-occupying lesions and changes in the liver’s structure.

MRCP (Magnetic Resonance Cholangio-Pancreatography)

This examination is particularly useful for assessing the bile ducts without the need for invasive procedures.

Histological examination

Liver biopsy

A liver biopsy remains the gold standard for diagnosing certain liver diseases. It is performed using ultrasound- or CT-guided needle biopsy and provides accurate information on the extent of inflammation, the degree of fibrosis and the specific type of disease.

When should we see a doctor?

Symptoms requiring urgent medical attention

Sudden, severe pain in the right side of the abdomen

The onset of jaundice

Vomiting blood or coffee-ground-like material

Black stools

Confusion, difficulty speaking (may be a sign of hepatic encephalopathy)

A scheduled medical examination is required

Abnormal liver enzyme levels in laboratory tests

Persistent tiredness and loss of appetite

Recurrent pain beneath the right rib cage

Liver diseases that occur amongst family members or acquaintances

Symptoms occurring whilst taking medication regularly

Interpreting liver enzyme levels

Slight increase (1–3 times the normal value)

A slight increase in liver enzymes is common and often does not require immediate treatment. Possible causes:

Side effects of medicines

Mild fatty liver

Viral upper respiratory tract infection

Alcohol consumption

Moderate increase (3–10 times the normal value)

In the event of a moderate increase, further investigations are required:

Viral hepatitis serology

Testing for autoimmune markers

Imaging examination

An overview of medicines and dietary supplements

A significant increase (10 times higher than the normal value)

If the values are high, urgent investigation is required:

Acute viral hepatitis

Drug-induced liver damage

Acute liver failure

Acute flare-up of autoimmune hepatitis

Interpreting the AST/ALT ratio

AST/ALT < 1: Typically indicates viral hepatitis or biliary obstruction

AST/ALT > 2: Characteristic of alcoholic liver disease or cirrhosis

AST/ALT = 1–2: The results are inconclusive; further investigations are required

Treatment options

Lifestyle changes

Giving up alcohol
In the case of alcohol-related liver disease, abstinence is the only effective treatment. Even reducing alcohol consumption can lead to significant improvement.

Weight loss
The cornerstone of treatment for non-alcoholic fatty liver disease is achieving a healthy weight. Even a weight loss of 5–10% can lead to a significant improvement in liver function test results.

Dietary changes

Eating less saturated fat and simple carbohydrates

Foods rich in fibre

A moderately reduced-calorie diet for those who are overweight

Medication

Viral hepatitis

Hepatitis B: Nucleoside/nucleotide analogues (entecavir, tenofovir)

Hepatitis C: Direct-acting antivirals (DAAs)

Autoimmune liver diseases

Autoimmune hepatitis: A combination of corticosterone and azathioprine

Primary biliary cholangitis: Ursodeoxycholic acid (UDCA)

Supportive care

For itching: cholestyramine, rifampicin

Vitamin supplementation with fat-soluble vitamins (A, D, E, K)

Prevention and lifestyle advice

General liver protection

Moderate alcohol consumption

For women: a maximum of 1 drink per day

For men: a maximum of 2 drinks per day

At least two alcohol-free days a week

The prudent use of medicines

Taking only medicines prescribed by a doctor

Adherence to the maximum daily dose of paracetamol (4 grams)

Consulting a doctor about the use of dietary supplements

Prevention of infections

Vaccination against hepatitis A and B

Safe sexual practices

Use of personal hygiene products

Nutritional recommendations

The basics of a liver-friendly diet

Eating plenty of fruit and vegetables

Choosing wholegrains

Lean sources of protein (fish, poultry, pulses)

Intake of omega-3 fatty acids (fish, walnuts, linseeds)

Foods to avoid

Over-processed foods

Trans fats and saturated fats

Excessive sugar consumption

Salty, smoked foods

Long-term tracking and monitoring

Regular inspections

Once abnormalities in liver enzyme levels have been detected, it is important to undergo regular medical check-ups. The frequency of these check-ups depends on the type and severity of the condition:

In the event of minor discrepancies

Laboratory check-ups every 3–6 months

Assessing the impact of lifestyle changes

In cases of chronic liver disease

A check-up with a specialist every 3–4 months

Annual imaging scan (ultrasound)

Screening for hepatocellular carcinoma

Prevention of complications

Screening for cirrhosis

Long-standing liver diseases can lead to cirrhosis. Key symptoms include:

Decrease in albumin levels

Rise in INR

Decrease in platelet count

The onset of ascites

Hepatocellular carcinoma (HCC) screening

In cases of cirrhosis, an abdominal ultrasound and an AFP tumour marker test are required every 6 months.

Frequently asked questions

How dangerous are elevated liver enzyme levels?

The risk posed by elevated liver enzyme levels depends largely on the extent of the increase and the underlying condition. Mild increases are often harmless, whilst significant increases may require urgent investigation. It is important to always interpret the levels in context – a temporary, mild increase is less cause for concern than a persistently elevated or gradually rising level.

Can liver enzyme levels return to normal?

Yes, in many cases liver enzyme levels can return to completely normal following appropriate treatment. The liver has an outstanding capacity for regeneration, and if the damaging factor is eliminated (for example, alcohol or harmful medicines), liver function can improve. Complete normalisation is often achieved following recovery from viral hepatitis, after the resolution of drug-induced liver damage, or as a result of lifestyle changes.

How often should the tests be repeated?

The frequency of the tests is determined by the doctor based on the extent of the abnormality and the suspected cause. Generally:

In the case of minor deviations: follow-up appointment in 4–12 weeks’ time

For moderate deviations: follow-up in 2–4 weeks’ time

In the event of serious deviations: immediate investigation and close monitoring

Can diet affect liver enzyme levels?

Yes, diet can have a significant impact on liver enzyme levels. Consuming high-fat, processed foods can lead to the development of fatty liver, whilst a balanced, fibre-rich diet supports liver function. Excessive alcohol consumption clearly damages the liver, whilst foods rich in antioxidants can have a protective effect.

Can stress cause elevated liver enzyme levels?

Chronic stress can indirectly affect liver function. Stress can lead to changes in eating habits, increased alcohol consumption or poorer sleep quality – all of which can have a negative impact on liver function. Although stress on its own rarely causes a significant rise in liver enzymes, managing stress can be part of maintaining liver health.

Can medicines be taken if liver enzyme levels are elevated?

This depends largely on the extent of the increase and the type of medication required. In the case of a mild increase, most medicines can be taken safely, although it is important to consult a doctor. Certain medicines known to cause liver damage should be avoided if there is a significant increase in liver enzymes. In all cases, the doctor will weigh up the need for treatment against the potential risks.

Summary and next steps

Discovering abnormal liver enzyme levels can often be a cause for concern, but it is important to know that, with early detection and appropriate treatment, most liver diseases can be managed effectively or even completely cured. The key lies in proper investigation and identifying the causes.

If you notice abnormal liver enzyme levels in your lab results, do not panic, but do not ignore them either. Consult your GP or a gastroenterologist, who will determine the necessary next steps. Early intervention and consistent treatment can significantly improve your prognosis and prevent complications from developing.

It is important to note that interpreting liver enzyme levels is a complex process that requires several factors to be taken into account. At Endomedix centres, you can receive specialist gastroenterological advice to help you make sense of your laboratory results and determine the most appropriate treatment plan tailored to your individual situation.

Remember: the liver is the only organ in our body capable of complete regeneration. With the right treatment and lifestyle changes, most liver diseases have a favourable prognosis, and patients can enjoy a long, healthy life.