What causes dehydration in the kidneys?
A high sodium diet can cause kidney stone formation (nephrolithiasis) and not drinking enough water can cause dehydration of the kidneys and the whole body as well.
The kidneys are designed to excrete waste products of the blood. If it cannot expel excess sodium in the body, it will cause kidney stone formation and dehydrate the kidneys together with the entire body. If one does not consume excess sodium which is around 2000mg/day but does not drink at least 8 glasses of water, sodium could still be deposited in the kidneys and cause dehydration and nephrolithiasis.