The liver is the body's largest single discrete organ. It has four major functions: metabolism and synthesis; excretion; storage; and the detoxification of potential poisons. These diverse functions mean that a single test does not give enough information to assess fully how the liver is functioning; at least five different liver function tests are required. This article, part 2 in a four-part series, discusses the information on acute and chronic liver disease that these tests can provide, and how disease affects liver function.