A person’s liver normally has a little amount of fat in it. Nonalcoholic fatty liver disease (NAFLD) is characterized by an accumulation of excess fat in the liver. It is not caused by alcohol consumption.
NAFLD is classified into two types: nonalcoholic fatty liver (NAFL) and nonalcoholic steatohepatitis (NASH) (NASH).
Weight loss is the sole suggested treatment for NAFLD, and there are no drugs available to treat either condition at this time.
Continue reading to learn about the symptoms, causes, and treatments of NAFLD, NAFL, and NASH, as well as the differences between the three.
NAFLD

The liver normally includes a tiny amount of fat, according to the American Liver Foundation (ALF).
Fatty liver, on the other hand, develops when fat accounts for more than 10% of the organ’s weight.
NAFLD is the leading cause of chronic liver disease in the United States, affecting up to 25% of the global population.
Symptoms
NAFLD is characterized as a silent disease because there are usually no symptoms of the condition.
Some people, however, may suffer symptoms such as:
- mental confusion
- swelling in the legs and abdomen
- weakness
- weight loss
- nausea
- abdominal pain
- fatigue
- jaundice
- loss of appetite
Causes
The ALF believes that approximately 100 million people in the United States have NAFLD. However, medical professionals do not fully comprehend what causes the condition. Although study is ongoing, scientists have established that certain health factors may lead to the development of NAFLD. The genetic make-up, food, and digestive system of a person may all have a role.
The following medical issues may increase a person’s risk of developing NAFLD:
- high levels of overall cholesterol
- metabolic syndrome
- underactive thyroid
- insulin resistance or type 2 diabetes
- having excess body weight or obesity
While researchers believe that some genes may have a role in the development of this condition, more research is needed.
Aside from the aforementioned concerns, many herbal medicines or dietary supplements can cause liver damage, so anyone who intends to begin taking supplements should always discuss the risks with their doctor.
Treatments
A person’s NAFLD can be controlled or even reversed by leading a healthy lifestyle, which may include eating a nutritious diet or decreasing weight. According to experts, decreasing weight can help reduce fat in the liver as well as inflammation and fibrosis.
Diagnosis
If a doctor suspects a patient has NAFLD, NAFL, or NASH, he or she may order a battery of tests to confirm the diagnosis. These could include:
- imaging tests
- a medical history
- a liver biopsy
- blood tests
NAFL
NAFL, also known as simple fatty liver, develops when a mostly harmless buildup of fat in the liver. Steatosis is the medical term for this condition.
According to the National Health Service (NHS) of the United Kingdom, most people will only ever develop NAFL and will not be aware of it.
However, NAFL can progress and cause liver damage in some people.
Symptoms
NAFL does not often cause liver inflammation or damage. People may experience pain if their liver is larger than usual due to the extra fat in the organ’s cells. Typically, NAFL does not progress.
Causes
Fatty liver is not always caused by NAFLD. Before concluding that NAFLD is the cause of a person’s fatty liver, doctors may want to rule out other possibilities.
Fatty liver, for example, can be caused by:
- taking certain medications
- toxin exposure
- alcohol-associated liver disease
- Wilson’s disease or other rare genetic diseases
- losing weight too quickly
Treatments
According to the National Institute of Diabetes and Digestive and Kidney Diseases, lifestyle adjustments may be able to prevent or reduce a person’s risk of getting NAFLD.
These are some examples:
- following a nutritious diet
- limiting portion sizes
- regular physical activity
- maintaining a moderate weight
Losing between 3% and 5% of a person’s body weight will often reduce fat in the liver.
Diagnosis
Because there are no symptoms, doctors frequently find NAFL when conducting medical tests for other reasons. A blood test, for example, will reveal high levels of liver enzymes. Further investigations, such as a comprehensive medical history and physical examinations, may be recommended by healthcare professionals.
NASH
Inflammation and liver damage occur when a person has NASH and high levels of fat in their liver.
Inflammation and liver damage can result in:
- liver fibrosis, or scarring of the liver
- cirrhosis
- liver cancer
- liver failure
Symptoms
Again, NASH normally has no symptoms, but some people may develop cirrhosis as a result.
Cirrhosis symptoms include:
- spider veins, which are visible blood vessels close to the surface of the skin
- swelling in the abdomen
- intense itching
- being quick to bruise and bleed
- jaundice, which refers to yellowing of the eyes and skin
If a person has any of the following symptoms, he or she should seek immediate medical attention:
- vomiting blood
- dark or black tarry stools
- fever
- slurred speech, and mental confusion
- shortness of breath
Cirrhosis, if left untreated, can cause the liver to fail: Because the liver controls so many other body systems, it can cause a variety of health problems if it is not functioning properly.
Causes
According to the ALF, around 20% of people with NAFLD will acquire NASH. NASH is more common in older people, although it can also affect youngsters.
NASH is also more probable in people who have:
- insulin resistance or type 2 diabetes
- high blood pressure
- excess weight or obesity
- obstructive sleep apnea
- body fat concentrated around the waist
Treatments
People should try to shed between 7% and 10% of their body weight to minimize liver inflammation and fibrosis. Experts advise doing this gradually rather than hastily, as decreasing weight too quickly can aggravate liver disease.
Doctors may prescribe drugs to manage NASH problems, which may necessitate minor medical treatments or surgery. People suffering from liver failure or cancer may require a liver transplant.
Diagnosis
Because a liver biopsy is required to determine how far the condition has progressed, it is the only test that can diagnose NASH. Liver biopsies can rule out other illnesses or provide a clearer picture of advanced liver disease or cirrhosis than imaging tests.
Similarities and differences between NAFL and NASH
NAFL | NASH | |
Full name | Nonalcoholic fatty liver | Nonalcoholic steatohepatitis |
Excess fat in the liver | Yes | Yes |
Inflammation | No | Yes |
Liver damage | No | 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 |
Conclusion
NAFL, NAFLD, and NASH are all related in that they are both types of NAFLD.
While NAFL is easily curable and reversible, NASH may progress to the point where all that can be done is avoid additional harm.
The best treatment for all types of nonalcoholic fatty liver diseases is to lose weight slowly and steadily.
Sources:
- https://www.niddk.nih.gov/health-information/liver-disease/nafld-nash/eating-diet-nutrition
- https://www.niddk.nih.gov/health-information/liver-disease/nafld-nash/definition-facts
- https://liverfoundation.org/for-patients/about-the-liver/diseases-of-the-liver/nonalcoholic-steatohepatitis-information-center/nash-causes-risk-factors/
- https://www.medicalnewstoday.com/articles/what-are-the-similarities-and-differences-between-nafl-nafld-and-nash
- https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5502701/
- https://www.nhs.uk/conditions/non-alcoholic-fatty-liver-disease/
- https://www.niddk.nih.gov/health-information/liver-disease/nafld-nash
- https://liverfoundation.org/wp-content/uploads/2019/11/NAFLD-Brochure-English.pdf
- https://www.niddk.nih.gov/health-information/liver-disease/nafld-nash/symptoms-causes
- https://britishlivertrust.org.uk/information-and-support/liver-health-2/symptoms-of-liver-disease/
- https://liverfoundation.org/wp-content/uploads/2018/04/ALF-NAFLD-NASH-Infographic.pdf
- https://www.liverhealthuk.com/post/what-is-the-difference-between-fatty-liver-and-nash