The order of chest percussion is generally from the top to the bottom of the thorax, and from the outside to the inside. Generally, the left side is first percussed from the outside of the thorax to the inside, and when the percussion reaches the midclavicular line about 2 cm inward, the clear tone becomes a turbid tone, marked with a marker, and then the place where the clear tone becomes a turbid tone is marked by the downward percussion. Similarly, on the left side, tap downward from the top to mark the place where the clear tone becomes turbid, and then tap out the turbid boundary of the heart. In addition, when tapping down to the left side, generally the ninth intercostal space changes from a clear tone to a turbid tone, which is the turbid boundary of the spleen; when the right side reaches the ninth intercostal space, it becomes turbid to indicate the upper boundary of the liver.