The kidneys are key organs that handle growth, making babies, and keeping your body's water balance just right. They also store good stuff that you get from your parents when you're born. In a way, kidneys are like the roots of your life. Some people even believe that how you grow starts in the kidneys. So, when it comes to helping people grow well, sometimes folks focus on the kidneys.
The kidneys sit in your lower back area, which is why problems with your kidneys can make your lower back feel bad. Your kidneys have two parts: kidney yin, which is like the water part, and kidney yang, which is like the fire part.
As for the good stuff your kidneys store, it's two kinds of things. One, it's the good stuff from your other organs, like your heart and lungs, which comes from food and drink that's been turned into useful stuff by your spleen. The kidneys keep this for later use. Two, it's also good stuff that your kidneys have on their own, from when you were born. This has to do with making babies, growing, and getting older.
When your kidneys don't have enough of this good stuff, problems can happen. For men, it might mean not having enough to make babies. For women, it can lead to problems like not having their monthly cycle and also not being able to make babies. Both men and women might not grow well and could age faster. To help with this, people work on making the kidneys stronger.