腎臟功能異常是肝硬化患者常見的一種情況，而腎功能同時也是預測患者預後的重要因子，尤其是在接受肝臟移植的患者，患者的肌酸酐是用來評估患者預後的重要因子之一。腎功能異常的原因有許多，包括肝硬化導致的肝腎症候群、腎臟本身的腎實質病變及許多可同時引發肝腎變化的疾病。雖然腎功能在肝硬化患者的角色非常重要，但最常用來評估腎功能的血清肌酸酐指數及其衍生的腎絲球過濾率公式皆有高估肝硬化患者腎功能的問題，因此，目前極需要方便且能準確檢測腎功能的工具及專為肝硬化患者設計的腎絲球過濾率公式。同樣的，將一般大眾用於急性腎臟損傷及慢性腎臟疾病的定義直接套用在肝硬化患者亦不恰當，且對腎臟功能異常分類的定義皆需再做檢討。本文針對肝硬化患者腎功能異常的原因、腎功能的評估、腎臟功能異常分類的定義作深入的探討，希望透過對『肝腎異常』更完整的了解，能制定更完善的治療方針。

Renal function impairment is an ominous and common event in cirrhotic patients. Serum creatinine is important in predicting short-term mortality and is used for the prioritization of liver transplant recipients in the United States. The causes of renal dysfunction include hepatorenal syndrome, renal parenchyma disease, or diseases affecting the liver and kidney. However, the serum creatinine and creatinine-based equations tend to overestimate renal function in patients with cirrhosis. A formula specifically derived for calculating GFR in cirrhotic patients is necessary. The present definitions of acute kidney injury and chronic kidney disease are not suitable for cirrhotic patients. This article discusses the causes and classification of renal dysfunction, evaluation of renal function, and defining hepatorenal disorders in cirrhotic patients.