Multicystic kidney disease is a genetic condition that leads to the development of cysts on one or both kidneys. These fluid-filled sacs gradually replace healthy kidney tissue and can cause complications such as high blood pressure, kidney pain, and kidney failure. Some synonyms for multicystic kidney disease include polycystic kidney disease, renal cystic disease, and cystic renal dysplasia. Polycystic kidney disease is a more commonly used term and refers to a group of genetic disorders that cause the formation of multiple cysts in the kidneys. Cystic renal dysplasia, on the other hand, is a very rare form of multicystic kidney disease that is often diagnosed in infants.