Liver failure is severe deterioration of liver function. Liver failure occurs when a large portion of the liver is damaged beyond repair due to any type of liver disorder, leaving the liver unable to function any longer. Liver failure is a potentially life-threatening condition and requires immediate medical care. In most cases liver failure occurs gradually and over a period of many years. However, a more rare condition known as acute liver failure occurs rapidly (in as little as 48 hours) and can be difficult to detect initially.