The "spleen deficiency" and "kidney deficiency" in traditional Chinese medicine refer to different disease processes. When spleen deficiency occurs, the severity of the condition is mild, while when kidney deficiency occurs, it is severe. Therefore, traditional Chinese medicine has the saying 'prolonged illness affects the kidney'. The meaning is that at the time of "kidney deficiency", there is significant functional damage, which may even affect energy metabolism. So, people with "kidney deficiency" will be afraid of the cold. If young people have "kidney deficiency", it is equivalent to premature aging, and young people will also be afraid of the cold. Some people only have partial fear of the cold, which is actually a local "kidney deficiency". These areas that are afraid of the cold are generally injured or have old problems. Because there is damage in certain areas, the body needs to constantly repair. Repairing requires energy, which dissipates too much and cannot be supplied, leading to local cooling.
The initial symptom of many cancer patients is that they are afraid of the cold in the area where they used to have old problems, and feel uncomfortable when encountering the cold, ultimately leading to cancer transformation. If you look at traditional Chinese medicine, you may be diagnosed with "kidney deficiency" when you feel cold. At this time, timely use of traditional Chinese medicine to tonify the kidney can reverse the situation of "kidney deficiency" and even prevent the occurrence of cancer. This is also why in traditional Chinese medicine research on esophageal cancer in the past, the "Six Flavors Dihuang Pills" for tonifying the kidneys were used to reverse the pre cancerous transformation of esophageal cancer cells. That's why.
The reason why people tend to equate "kidney deficiency" with reproductive dysfunction is because reproductive function is secondary to the energy generation that ensures vitality. Human reproductive function, like the tail of a gecko, can only be achieved after preserving life. In order to preserve life, the already weakened body will first lose its reproductive function, similar to "sacrificing the chariot to protect the handsome", which is also a kind of life wisdom, at least to "save energy" for the already weak body.