Liver disease may be the result of a variety of causes, including developmental or genetic defects, metabolic abnormalities, autoimmune diseases, infectious diseases, neoplasm, alcohol, environmental toxins, and drug toxicity.
Liver disease can be divided into hepatocellular (parenchymal) or biliary. In hepatocellular diseases, evidence of cholestasis and synthetic dysfunction appear synchronously.
Liver disease may also be described as acute (drug toxicity, infection) or chronic (viral hepatitis, alcoholic liver disease, nonalcoholic fatty liver disease [NAFLD]). The most common causes of chronic liver disease are chronic viral hepatitis, alcoholic liver disease, and NAFLD. The most important consequences of chronic liver disease are portal hypertension, cirrhosis, and malignancy.