Urogenital illnesses are conditions that affect the urinary tract (kidneys, ureters, bladder, and urethra) or the reproductive organs (genitals). Common urogenital diseases include kidney stones, infections, tumors, and disorders of the male and female reproductive systems. The word "urogenital" comes from the Greek words oros (ore) + gennete (generation). It means "of the kidneys/bladder." In medical terminology, diseases that involve these areas of the body are called renal/urinary tract diseases and sexual-organ diseases, respectively. Diseases of the genitourinary system account for 12% of all human deaths. The number one cause of death due to a single condition is nephritis (kidney disease), which can lead to end-stage renal disease (ESRD). ESRD patients require regular visits to a nephrologist (a doctor who specialises in kidney diseases) for dialysis or transplantation of their diseased kidneys.