The number of eight diagrams and hexagrams is 6, the orientation is north, the season is winter, the five elements belong to water, and the five internal organs are kidneys. The kidney controls the bone to produce marrow, and it is enlightened to the ear and the second yin. The corresponding human parts are waist, back, lower orifices and ears. Kidney and bladder are exterior and interior, and the meridians related to kidney are the kidney meridian of foot shaoyin and the bladder meridian of foot taiyang.

The five colors of the five internal organs are not imagined by people, but they do exist, but ordinary people can't see them. The essence of kidney qi is deep purple, mainly black. Of course, this does not refer to the color of the kidney, but refers to the kidney qi.

The ear is related to the kidney, but not only to the kidney. Because the liver and gallbladder are too dry and the wood fire is too strong, it is necessary to soothe the liver and benefit the gallbladder, cool the blood and benefit the water, and contain wood. If tinnitus is the first offense or intermittent tinnitus, you can read 006400 and write it behind your ear to improve the symptoms. Long-term adherence to reading and the number of images can also cure tinnitus. Of course, this requires a lot of work.