Cirrhosis is a chronic, progressive liver disease characterized by diffuse damage to liver cells and the replacement of liver tissue with fibrosis and regenerating nodules, resulting in loss of liver function. It is caused by repeated injury and death of liver cells, which leads to scarring as the liver tries to heal. Common causes include alcohol abuse, viral hepatitis, and genetic conditions. Cirrhosis symptoms include fatigue, abdominal pain, jaundice, edema, and gastrointestinal bleeding due to complications like portal hypertension. The only way to diagnose cirrhosis definitively is through a liver biopsy.