A fluid dark area in the liver is usually a descriptive term for an imaging test, which can be considered as a liver cyst or subperitoneal hemorrhage, etc., and requires prompt medical attention once detected. Specifically, fluid dark areas in the liver is a term used in ultrasound because ultrasound waves do not usually penetrate well into fluid collections during ultrasound of the liver, thus presenting a dark area. It is usually a cystic mass in the liver called a hepatic cyst, which is a common benign liver lesion with symptoms such as early satiety or indigestion. Secondly, a fluid dark area in the liver may also be a subpericardial hemorrhage, which is usually caused by trauma and is a blunt contusion, and in severe cases, can lead to rupture of a blood vessel in the liver and secondary bleeding. It is recommended to actively seek medical advice and follow the doctor’s instructions for examination and treatment.