Liver cirrhosis is a severe, progressive disease in which healthy liver tissue is irreversibly replaced by fibrous (scar) tissue. Fibrosis occurs as a result of excessive proliferation of collagen-producing cells and the growth of blood vessels that penetrate the liver. In some cases, the cause of cirrhosis becomes known as the primary, or cause of the disease. In such cases, they talk about specific cirrhosis - for example, primary biliary cirrhosis (PBC), acquired viral cirrhosis, etc. Sometimes the exact cause of the development of cirrhosis cannot be established; this condition is called idiopathic if there is no visible cause.