A mobile turbid tone is an ancillary test used to check for abdominal normality. A positive mobile turbid sound is a reliable sign of free fluid in the abdominal cavity. A mobile turbid sound can be detected when there is more than 1000 ml of free ascites in the abdominal cavity. A turbid tone is a non-musical percussion sound with a higher pitch, weaker sound and shorter vibration duration, produced when percussing a parenchymal organ covered by a small amount of air-containing tissue, such as percussing the part of the heart or liver covered by the edge of the lung, or in pathological states such as pneumonia (reduced air content of lung tissue). In the abdomen, percussion is a drum sound, i.e. drumming, in normal people. However, when there is a large amount of fluid in the abdominal cavity, i.e. “ascites”. It reaches 1000 ml. The abnormal mobile turbid sound can be produced: mobile turbid sound is a common diagnostic method to check the presence of ascites. A mobile turbid sound (-) is normal; a mobile turbid sound (+) indicates the presence of ascites. The sound produced by percussion of a parenchymal organ covered by a small amount of air-containing tissue, such as percussion of the part of the heart or liver covered by the edge of the lung, or the percussive sound exhibited in pathological states such as pneumonia (reduced air content of lung tissue). People to be examined: Routine physical examination items, abdominal abnormalities. Precautions: Unsuitable population: basically no unsuitable population, but those with psycho-psychiatric abnormalities should be noted. Requirements for examination: The following conditions may be mistaken for ascites: when there is a large amount of fluid retention in the intestinal canal, mobile turbid sounds may appear due to the movement of the patient’s body position, but they are often accompanied by signs of intestinal obstruction; huge ovarian cysts may also cause large turbid sounds in the abdomen, but their turbid sounds are non-mobile. The examination procedure: Have the subject lie on his back, start from the middle of the abdomen and percuss to both sides of the abdomen. If the amount of ascites is small and cannot be detected by the above method, the patient can be placed in the elbow and knee position so that the umbilicus is at the lowest part. Percussion from the lateral abdomen to the umbilicus, if the sound changes from a drum to a turbid sound, it suggests the possibility of ascites. The patient can also be made to stand, and the lower abdomen is cloudy with fluid, and the upper boundary of the fluid is a horizontal line, in which the floating intestinal curvature is percussed with a drum sound.