Below is an instruction from Human. Write a response.
    ### Instruction:
    What is (are) Budd-Chiari syndrome ?
    ### Response:
    Budd-Chiari syndrome is a rare disorder characterized by narrowing and obstruction of the veins of the liver. This narrowing or obstruction slows or prevents blood from flowing out of the liver and back to the heart which can lead to liver damage. While some people experience no symptoms, many experience fatigue, abdominal pain, nausea, and jaundice.
    