Nephrology is the specialty of medicine that concerns itself with the diagnosis and treatment of diseases of the kidney. Physicians specializing in this field are called nephrologists or kidney specialists. Urology is the medical field concerned with the diagnosis and treatment of conditions involving the urinary tract and male reproductive system.  This involves the kidneys, urinary bladder, genital structures in males and females, and the prostate and testicles in males.  Urologists are specially trained to evaluate these systems so as to optimize their functioning and enhance quality of life.