What is steatotic liver disease?

Your liver is the largest organ in your body. It weighs about 1.5 kg in the average adult, is about the size of a football and sits under your ribs on the right side of your body. It’s spongy, reddish-brown in colour and has a wedge shape. Your liver also has the ability to regenerate itself! 

Your liver does over 500 different things to keep you healthy!¹ The two most important are cleaning your blood and helping with digestion. Almost everything you eat, and drink is processed by your liver. Your liver also: 

• cleans out the things your body can’t use (e.g. alcohol and toxins)  
• makes and stores vitamins and minerals including iron which is needed to carry oxygen throughout the body 
• helps produce hormones that support mental health 
• regulates energy levels by storing and releasing sugars 
• makes the building blocks your body needs to make new cells. 

If you don’t have a healthy liver, it’s harder for your body to function normally. One condition that can affect your liver is steatotic liver disease. 

Steatotic (pronounced stee-uh-TOT-ik) liver disease (SLD) is commonly known as fatty liver disease. It’s a condition when there is too much fat in your liver. Over time, this can be a problem and lead to serious liver conditions such as cirrhosis (scarring of the liver that causes it to stop working properly) and liver cancer. 

A healthy liver has very little or no fat. Steatotic liver disease is diagnosed when > 5% of liver cells have fat deposited within them.² This is usually caused by a combination of factors over a long period of time. 

Before we get into the details of steatotic liver disease, it’s important to understand the terminology around this condition, as many of the terms traditionally used to describe fatty liver disease have changed. 

The term ‘fatty liver’ is now outdated. In June 2023, the American Association for the Study of Liver Disease (AASLD) chose a new term ‘Steatotic liver disease (SLD)’ to describe fatty liver disease.^{3 4}

There are several reasons this term was chosen. For example, it:

• more accurately reflects what causes too much fat on the liver
• helps to describe how complex and serious this condition is
• removes the association with alcohol consumption, which can be confusing.

Other organisations outside America, are now using these terms including the British Liver Trust.

The term ‘steatotic’ refers to the process of ‘steatosis’, which is a complex term for fat build-up in the liver. Doctors may also call steatotic liver disease ‘hepatic steatosis’ (hepatic refers to liver). 

Sub-groups of steatotic liver disease 

Steatotic liver disease is an umbrella term used to describe various causes of what was previously known as fatty liver disease. There are four sub-groups of SLD,⁵ but they are all managed in similar ways. 

• Metabolic dysfunction Associated Steatotic Liver Disease (MASLD) (pronounced MA-zuld) — This is when steatosis is caused by factors other than excessive alcohol use. It’s usually associated with high cholesterol, being overweight, and diabetes. MASLD used to be known as NAFLD (non-alcoholic fatty liver disease). 
• Metabolic-Associated Steatohepatitis (MASH) — This is a more serious form of MASLD. MASH used to be called NASH (non-alcoholic steatohepatitis).  
• MetALD (pronounced: Met A-L-D) — This is when people have MASLD with increased alcohol intake. This is a new term. 
• Cryptogenic SLD — This is when people have fatty liver disease without any known cause or any metabolic risk factors. This is a new term. 

This might all sound confusing. But you don’t have to remember all the terms and the reasons why they were chosen.  

All you need to remember is that steatotic liver disease (sometimes called MASLD) is the new term for ‘fatty liver’ — a condition where there is too much fat in your liver. 

Steatotic liver disease is a growing concern around the world, including Australia. Over the past 15 years, rates of SLD have risen in Australia.⁶

Currently, about one in every three people in Australia have SLD. It’s expected that within the next 20 years, SLD will be the leading cause of liver transplant.⁷

In its early stages, SLD doesn’t usually cause symptoms so many people won’t know they have a problem. Most people with SLD won’t develop long-term problems with their liver. However, fat on the liver can increase your risk for other conditions such as heart disease, diabetes, kidney disease and cancer.⁸

Some people with SLD can end up with serious damage to their liver, including: 

• inflammation  
• fibrosis (when a band of scar tissues forms) which causes the liver to become stiff 
• cirrhosis (when extensive scar tissue replaces healthy tissue), and stops the liver from working properly 
• liver failure 
• liver cancer. 

Some people with advanced liver disease may need a liver transplant. 

The good news is, there is a lot you can do to take care of your liver and keep it healthy. Early stages of SLD can also be reversed. This is because of our liver’s amazing ability to heal and regenerate itself.⁹