Renal vein thrombosis (RVT) is the formation of a clot in the vein that drains blood from the kidneys, ultimately leading to a reduction in the drainage of one or both kidneys and the possible migration of the clot to other parts of the body. First described by German pathologist Friedrich Daniel von Recklinghausen in 1861, RVT most commonly affects two subpopulations: newly born infants with blood clotting abnormalities or dehydration and adults with nephrotic syndrome.Nephrotic syndrome, a kidney disorder, causes excessive loss of protein in the urine, low levels of albumin in the blood, a high level of cholesterol in the blood and swelling, triggering a hypercoagulable state and increasing chances of clot formation. [Source: Wikipedia ]