Budd–Chiari syndrome is a very rare condition. It is an uncommon condition induced by thrombotic or nonthrombotic obstruction of the hepatic venous outflow and is characterized by hepatomegaly, ascites, and abdominal pain. It is caused by blood clots that completely or partially block blood flow from the liver. It usually occurs when a clot narrows or blocks the hepatic veins, which carry blood out of the liver.