A person’s liver usually contains a small amount of fat. However, nonalcoholic fatty liver disease (NAFLD) is where an individual has a store of excess fat in their liver. It does not result from alcohol use.
There are two types of NAFLD: nonalcoholic fatty liver (NAFL) and nonalcoholic steatohepatitis (NASH).
Weight loss is the only recommended treatment for NAFLD, and there are currently no medications to treat either condition.
Read on to find out the symptoms, causes, and treatments of NAFLD, NAFL, and NASH and the differences between the three.
According to the American Liver Foundation (ALF), the liver typically contains a small amount of fat.
However, fatty liver occurs when more than 10% of this organ’s weight comprises fat.
NAFLD is the most common cause of chronic liver disease in the United States and affects up to 25% of the world’s population.
NAFLD is known as a
However, some people may experience symptoms such as:
- abdominal pain
- loss of appetite
- mental confusion
- swelling in the legs and abdomen
- weight loss
The ALF estimates that around 100 million people in the U.S. have NAFLD. However, health experts do not fully understand what causes the condition. Studies are continuing, but researchers have concluded that certain health conditions may contribute to the development of NAFLD. A person’s genetic makeup, diet, and digestive system may also play a role.
Health conditions that may make an individual more likely to develop NAFLD include:
- having excess body weight or obesity
- insulin resistance or type 2 diabetes
- high levels of overall cholesterol
- metabolic syndrome
- underactive thyroid
And while researchers believe specific genes may contribute to developing this condition, further studies are necessary.
As well as the above, certain herbal remedies or dietary supplements can
A person can control or even reverse NAFLD through healthy living, which may involve following a nutritious diet or losing weight. Experts suggest losing weight can help reduce fat in the liver as well as reduce inflammation and fibrosis.
If healthcare providers suspect a person has NAFLD, NAFL, or NASH, they may order various tests to confirm. These may include:
- a medical history
- blood tests
- imaging tests
- a liver biopsy
Also known as simple fatty liver, NAFL occurs when there is a mainly harmless build-up of fat in the liver. It is known as steatosis.
According to the United Kingdom’s National Health Service (NHS), most people will only ever develop NAFL and not usually realize it.
However, NAFL may progress for some individuals and cause liver damage.
NAFL typically does not cause liver inflammation or damage. However, because the liver may be larger than usual due to the additional fat in the organ’s cells, people may experience pain. Usually, NAFL will not progress.
Fatty liver is not necessarily due to NAFLD. Doctors may wish to look into alternative diagnoses before settling on NAFLD as the cause of a person’s fatty liver.
For example, fatty liver can also
- alcohol-associated liver disease
- losing weight too quickly
- taking certain medications
- toxin exposure
- Wilson’s disease or other rare genetic diseases
According to the
- regular physical activity
- maintaining a moderate weight
- following a nutritious diet
- limiting portion sizes
Often, losing between
As there are no symptoms, doctors usually only discover NAFL when carrying out medical tests for other reasons. For example, a blood test will show high levels of liver enzymes. Healthcare professionals may then wish to carry out further investigations, such as a complete medical history and physical examinations.
If a person has NASH and high levels of fat in their liver, they also have inflammation and liver damage.
This inflammation and liver damage can lead to:
- liver fibrosis, or scarring of the liver
- liver cancer
- liver failure
Again, there are often no symptoms for NASH, but some people may develop cirrhosis as a complication.
Symptoms of cirrhosis include:
- being quick to bruise and bleed
- intense itching
- jaundice, which refers to yellowing of the eyes and skin
- spider veins, which are visible blood vessels close to the surface of the skin
- swelling in the abdomen
It is essential to seek urgent medical attention if a person experiences any of the following symptoms:
- shortness of breath
- vomiting blood
- dark or black tarry stools
- slurred speech, and mental confusion
Without treatment, cirrhosis can cause the liver to stop functioning: A range of different health issues can result from the liver not working correctly, as it controls so many other bodily functions.
The ALF estimates that about 20% of people with NAFLD will develop NASH. Older individuals are also more likely to develop NASH, but some children may get it.
NASH is also more likely to occur in people with:
- excess weight or obesity
- body fat concentrated around the waist
- insulin resistance or type 2 diabetes
- high blood pressure
- obstructive sleep apnea
To reduce liver inflammation and fibrosis, people should aim to lose between
Doctors may use medications to treat complications of NASH, which may require minor medical procedures or surgery. People experiencing liver failure or liver cancer may need a liver transplant.
|Full name||Nonalcoholic fatty liver||Nonalcoholic steatohepatitis|
|Excess fat in the liver||Yes||Yes|
|Reversible||Usually||Depends on progression|
|Treatment||3–5% body weight loss||7–10% body weight loss|
|Possible complications||Typically none||Fibrosis, cirrhosis, liver cancer, liver failure|
NAFL, NAFLD, and NASH are connected, in that NAFL and NASH are both types of NAFLD.
While NAFL is easily treatable and reversible, NASH may advance to a stage where all a person can do is prevent further damage.
Slowly and steadily losing weight is the best treatment for all forms of nonalcoholic fatty liver conditions.