The damage that occurs is similar to that caused by drinking too much alcohol, but fatty liver disease affects people who drink little or no alcohol. At its most severe, the condition can progress to cirrhosis and liver failure. Around 20% of people with non-alcoholic fatty liver disease develop cirrhosis.
Fatty liver is characterised by liver inflammation, which may results in scarring and irreversible damage. The condition is increasingly common in the Western world and is now the number one form of chronic liver disease in the United States.
It mostly affects people in their 40s and 50s who are also at risk of heart disease due to obesity and type 2 diabetes. It is linked to metabolic syndrome, which is a range of abnormalities including increased abdominal fat and poor insulin use.
It is not clear why some people develop accumulations of fat in the liver and others don’t, or why some people with fatty livers go on to develop cirrhosis while others do not. However, there are certain risk factors that increase your likelihood of developing the disease, including:
- Being overweight or obese, particularly when fat is concentrated around the stomach
- Insulin resistance
- Being over the age of 40
- High cholesterol
- High levels of fat in the blood, particularly triglycerides
- High blood sugar which may be an indicator of pre-diabetes
- Type 2 diabetes
- Polycystic ovary syndrome
- Sleep apnoea
- Underactive thyroid (hypothyroidism)
- Underactive pituitary gland (hypopituitarism)
- Metabolic syndrome
Fatty liver may not cause any symptoms but where there are symptoms they might include:
- An enlarged liver
- Pain in the upper right of the abdomen
When the condition progresses to cirrhosis you might experience:
- Scarring (fibrosis) of the liver as it attempts to halt the inflammation. Over time, fibrosis takes up more and more liver tissue
- Yellowing of the skin and eyes (jaundice)
- Abdominal sweating
- Enlarged spleen
- Fluid build-up in the abdomen
- Swelling of the veins in the oesophagus, which can rupture and bleed
- Hepatic encephalopathy which causes slurred speech, confusion and drowsiness
- Liver cancer
- Liver failure, which means the liver no longer functions
- Blood testing which might measure liver enzyme and function, test for viral hepatitis and show blood sugar levels. They can also measure the level of fat in your blood and screen for celiac disease.
- Diagnostic imaging, including:
- Ultrasound. Transient elastography is a form of ultrasound that measures how stiff the liver is, which is an indicator of scarring.
- CT or MRI scans of the abdomen. Magnetic resonance elastography combines MRI with sound waves to create a visual map of the liver, showing areas of scarring.
- Liver biopsy which is carried out by inserting a needle through the abdominal wall into the liver. This will normally only be performed if less invasive tests prove inconclusive.
Symptoms may improve after a loss of 3-5% of body weight but 10% is desirable.
In some cases, weight loss surgery may be recommended. If you have diabetes you need to stay in control of your condition and closely monitor your blood sugar levels. Your doctor will advise you to avoid doing anything to put extra stress on your liver, such as drinking alcohol. You will also need to be careful about taking medication and herbal remedies which can be harmful to the liver.
To prevent further liver damage caused by viruses, you may receive vaccinations against hepatitis A and B.
If the condition has progressed to cirrhosis, you may be offered liver transplant surgery, which generally has good outcomes.
There are steps you can take to reduce your risk of fatty liver disease, particularly if you are at high risk of the condition. These include:
- Eat a healthy diet rich in fruit, vegetables, healthy fats and whole grains.
- Maintain a healthy body weight and take regular exercise.