Kidneys were organs located near the lower back on Humans. Although naturally having both a left and right kidney, Humans could survive with only one. Kidneys could be transplanted and even cloned if needed. Diffrent species can have a diffrent number of kidneys. For example members of the Yarkora species have four kidneys. Hitting a person in the kidneys caused extreme—often disabling—pain for the victim. Older Humans often suffered from Zithrom's Disease, which resulted in shrunken kidneys, among other symptoms. Kidney stones could accumulate within the kidneys and be passed from the body.