Although kidneys are clearly important for survival, they are not essential, and this is particularly true if only one kidney is present. Some people are born without one of their kidneys, a condition called renal agenesis. Some other...

Although kidneys are clearly important for survival, they are not essential, and this is particularly true if only one kidney is present. Some people are born without one of their kidneys, a condition called renal agenesis. Some other...