The condition can be broken down into four main stages.
The initial stage, known as steatosis, is characterised by a largely harmless build-up of fat in the liver cells.
Next is steatohepatitis (NASH), which describes inflammation of the liver, and is a more serious form of NAFLD.
Fibrosis is when persistent inflammation causes scar tissue to grow around the liver and nearby blood vessels, which doesn’t prevent the liver from functioning normally.
The final and most serious stage is cirrhosis, which usually occurs after years of inflammation, causing the liver to become scarred and lumpy.