Hepatorenal syndrome is a form of impaired kidney function that occurs in individuals with advanced chronic liver disease. As many as 40% of individuals with cirrhosis and ascites will develop hepatorenal syndrome. Symptoms may include fatigue, abdominal pain, and a general feeling of ill health (malaise). There are two distinct types of hepatorenal syndrome. Type I progresses quickly (within days), leading to kidney failure. Individuals with type I typically have dramatically reduced urine output, edema, and jaundice, and often suffer from hepatic encephalopathy. Type II progresses more slowly, over weeks or months, and the symptoms are less severe. The cause of hepatorenal syndrome is unknown. A contributing factor seems to be a narrowing of the blood vessels that connect into the kidneys. This causes a decrease in blood flow to the kidneys, impairing their function. In some cases, triggers or precipitating factors (infections, blood loss from the gastrointestinal tract, low blood pressure) are involved. Treatment is aimed at helping the liver work better and maintaining kidney function. In many cases, a liver transplant is needed. In some cases, individuals also need a kidney transplant. The disease is Monarch Disease Ontology identifier MONDO_0001382 (hepatorenal syndrome).