Brief overview
- Symptoms: Initially hardly any symptoms, as disease progresses and liver inflammation is added, feeling of pressure/fullness in right upper abdomen, pain in liver area, nausea/vomiting, sometimes fever
- Treatment: mainly change in eating and exercise habits.
- Causes and risk factors: Non-alcoholic fatty liver is mainly associated with severe obesity, insulin resistance or diabetes mellitus, rarely drugs are the cause
- Course of the disease and prognosis: If left untreated, fatty liver often develops into inflammation of the liver (hepatitis) and eventually even cirrhosis of the liver, in which case there is a risk of severe complications, including liver failure. If fatty liver is treated in time, complete cure is possible
What is a fatty liver?
- Mild fatty liver: Less than one-third of liver cells are excessively fatty.
- Moderate fatty liver: Less than two-thirds but more than one-third of liver cells are excessively fatty.
- Severe fatty liver: More than two-thirds of liver cells are excessively fatty.
The exact extent of liver cell fatty degeneration can be determined by a fine tissue (histopathological) examination of a tissue sample from the liver (liver biopsy).
Almost all fatty liver patients are overweight. About one in two also suffers from diabetes mellitus or has elevated blood lipid levels. In addition, fatty liver often accompanies metabolic syndrome.
Last but not least, fatty liver is an important risk factor for liver cell cancer (hepatocellular carcinoma).
Frequency and classification of fatty liver
As the name suggests, alcohol is the trigger of alcoholic fatty liver (AFL) – more precisely, chronic alcohol abuse. If alcoholic fatty liver leads to liver inflammation, it is referred to as alcoholic steatohepatitis (ASH).
Non-alcoholic fatty liver diseases are regarded as a “disease of affluence. In industrialized countries, for example, they are occurring more and more frequently in children and adolescents because they are increasingly developing severe obesity, which is a central trigger of NAFLD. Non-alcoholic fatty liver (NAFL), for example, is significantly more common in overweight boys than in overweight girls.
How does a fatty liver manifest itself?
In most cases, blood pressure and blood lipid levels are elevated long before fatty liver symptoms appear. If the abdominal girth is also larger and there is insulin resistance, as in diabetes mellitus, increased attention should be paid to fatty liver symptoms.
Fatty liver symptoms with alcoholic cause
Even if increased alcohol consumption is the cause of fatty liver disease, no specific fatty liver symptoms initially appear. One indicator is usually alcohol consumption: in women, the critical limit for regular alcohol consumption is 20 g of alcohol per day (equivalent to about 0.5 l of beer), and in men this is 40 g per day.
Fatty liver symptoms with secondary diseases
The non-alcoholic fatty liver disease leads to liver inflammation (hepatitis) in about one in four, the alcohol-related form even in almost one in three affected persons. The symptoms of non-alcoholic fatty liver hepatitis (NASH) and alcohol-related fatty liver hepatitis (ASH) do not differ.
Liver inflammation symptoms
In fatty liver inflammation (steatohepatitis), there is a pronounced inflammatory reaction in the liver. A typical symptom of this inflammatory reaction is severe pain in the area of the liver, i.e. under the right costal arch. On the other hand, functional disorders of the liver occur due to the inflammation. For example, the blood breakdown product bilirubin is no longer metabolized sufficiently by the liver.
Fatty liver symptoms in liver cirrhosis
If the disease progresses unchecked, fatty liver may develop into cirrhosis, in which the connective tissue of the liver changes. Possible symptoms include:
- Feeling of pressure and fullness in the upper abdomen
- Nausea and vomiting
- Weight loss due to lack of appetite
- Yellowish discoloration of the skin and eyes (jaundice) due to elevated bilirubin levels in the blood
- Itching due to bilirubin or undegraded bile acids in the skin
- Red palms (palmar erythema)
- Noticeably red, shiny lips (“patent lips”)
- Water retention in the legs (leg edema) and abdomen (ascites)
- Visible blood vessels around the navel (caput medusae)
- Breast enlargement in men (gynecomastia)
- Reduced hairiness in the abdominal area in men (“belly baldness”)
- Blood clotting disorder; usually recognizable by increased nosebleeds and bruising
Fatty liver symptoms in liver failure
Unlike initial fatty liver, liver failure leads to symptoms that are unmistakable. The skin and the whites of the eyes are yellowish in color. Blood clotting is disturbed because the liver no longer produces clotting factors. Thus, even small bumps cause bruises. In the case of larger hemorrhages, the affected person may vomit blood or pass black stool.
Fatty liver disease often only becomes apparent when secondary diseases have already set in. To prevent these consequences, even non-specific fatty liver symptoms must be taken seriously, diagnosed quickly and treated.
How is a fatty liver treated?
There is therefore no specific drug therapy for fatty liver or one effective home remedy that will make it disappear. Rather, the aim of the therapy is to eliminate or treat the triggering causes.
Thus, a fatty liver can be reduced with a targeted change in lifestyle. Existing excess weight should be sustainably reduced with a low-fat, low-sugar and low-calorie diet and regular exercise.
Non-overweight fatty liver patients should also follow a low-fat and low-sugar diet. All patients with fatty liver should also avoid alcohol completely.
Read all about nutrition in fatty liver.
If patients with very severe overweight (obesity, BMI ≧35) do not lose weight despite diet and exercise program, there is the possibility of weight-reducing surgery in which the stomach is reduced in size (bariatric surgery).
Fatty liver treatment includes regular check-ups (such as measurement of liver values and ultrasound) to detect early progression of the disease into liver inflammation or possible cirrhosis.
If the liver tissue is completely destroyed, there is no longer any chance of curing the fatty liver. A liver transplant is then the last treatment option. If a suitable donor can be found, the liver of another person is used to take over the failed liver function.
Causes and risk factors
How fatty liver disease develops has not yet been clarified in detail.
There are various explanations for how this imbalance develops. One theory is that certain transporter proteins in the liver transport too many fats into the organ. In the case of vitamin B deficiency, on the other hand, the fat contained in the liver, for example, is not processed properly and accumulates.
Alcohol as a cause
However, these are only approximate guide values. Another decisive factor is how long the steady alcohol consumption has existed and whether metabolic diseases such as diabetes mellitus or obesity, rare congenital metabolic disorders or a hormonal imbalance (polycystic ovary syndrome, PCOS) are also present.
Nevertheless, not all people who drink alcohol develop a fatty liver. This is due to individual sensitivity, gender and the individual’s endowment with enzymes that break down alcohol.
Diet, obesity and diabetes as risk factors
Non-alcoholic fatty liver disease is often associated with increased caloric intake and an elevated body mass index (BMI) as a measure of obesity. Severe fat deposits on the abdomen (visceral obesity) are particularly dangerous.
The inadequate uptake of blood sugar into the body’s cells causes the cells to suffer from a lack of energy. To compensate, the body increasingly breaks down stored fat, which now provides energy instead of sugar. More free fatty acids enter the blood, and the liver cells absorb more of them. This promotes fatty degeneration of the liver.
Type 2 diabetes is a very important trigger of non-alcoholic fatty liver disease. There is also a correlation in the opposite direction: patients with non-alcoholic fatty liver develop type 2 diabetes more frequently than people without a fatty liver.
Other risk factors
Rare causes of fatty liver
However, overly fatty foods or diabetes are not always to blame for non-alcoholic fatty liver. Other possible triggers of fatty liver include prolonged periods of starvation, marked weight loss, long-term sugar infusions (for example, in the case of pancreatic defects), and artificial nutrition.
In addition, there are operations on the small intestine, liver and pancreas, after which there is increased fat storage in the liver.
Furthermore, inflammatory bowel diseases (such as Crohn’s disease) are rare but possible causes of fatty liver.
Examinations and diagnosis
Anyone who suspects they have fatty liver should consult their primary care physician or an internist.
Medical history and physical examination
To diagnose a fatty liver, the doctor first asks about symptoms and existing diseases (medical history). Possible questions of this interview are:
- Do you drink alcohol and if so, how much?
- What is your diet?
- What medications are you taking?
- Are you known to have diabetes mellitus?
- How much do you weigh?
The interview is followed by a physical examination. Among other things, the doctor will palpate the liver through the abdominal wall. If it is enlarged (hepatomegaly), this indicates a fatty liver. However, there are many other causes of liver enlargement and this is not specific to fatty liver.
During a physical examination, it is sometimes possible for the physician to palpate the enlarged liver. At the latest, the altered liver structure then becomes visible during abdominal ultrasound.
Further examinations
Blood tests are also helpful in clarifying possible fatty liver disease. If certain values are permanently elevated in the blood test, this is an indication of fatty liver.
However, elevated liver values are not a specific fatty liver symptom, but only a general indication of liver damage, regardless of the cause. An increase in lactate dehydrogenase (LDH) also indicates acute hepatitis, i.e. liver inflammation.
In order to determine the exact extent of the fatty liver and, if necessary, to obtain clues as to the cause, a liver biopsy may be performed. Under local anesthesia, the physician removes a small tissue sample from the liver using a thin hollow needle. This is then examined for fine tissue (histopathologically) under the microscope.
Fatty liver: Searching for the cause
Once the diagnosis of fatty liver has been established, it is important to clarify its cause. This sometimes requires further examinations. For example, determining blood glucose levels (fasting blood glucose, long-term blood glucose HbA1c) helps to find indications of insulin resistance or previously undetected diabetes.
Course of the disease and prognosis
In the case of fatty liver (steatosis hepatis), the prognosis depends on the one hand on how early the disease is detected and treated. On the other hand, it plays a role whether it is a fatty liver caused by alcohol consumption or not. If alcohol is the cause, the prognosis is somewhat worse. Nevertheless, it is initially a benign disease.
However, if fatty liver develops into cirrhosis, there is a risk of serious complications, including liver failure. The liver does not recover from cirrhosis. This is because the liver cells are destroyed and replaced by functionless scar tissue. To prevent this from happening, fatty liver should be treated as quickly as possible.