You are correct. Kidneys control many key functions of the body. My wife is on dialysis. When she first started she was given a prognosis of 3 to 5 years survival. Because she is so conscious of her health and prays a lot she has now lived 20 years.
We had no idea that kidneys control the regulation of so many things. They aid in blood pressure control. They regulate the amount of blood needed within the body. Without their function you must take Epogen which can lead to blood clots. They aid digestion. Many supplements must be taken daily to regulate these digestive processes when the kidneys are impaired.
Take care of your kidneys