Cirrhosis is a condition where normal liver tissue is replaced by scar tissue (fibrosis).
The 'scarring' tends to be a gradual process. The scar tissue affects the normal structure and regrowth of liver cells. Liver cells become damaged and die as scar tissue gradually develops. Therefore, the liver gradually loses its ability to function well.
This is a companion discussion topic for the original article at https://patient.info/digestive-health/abnormal-liver-function-tests-leaflet/cirrhosis