The term renal parenchyma refers to the functional parts of the human kidney, including the elements of the organ that create urine. The term differentiates the essential parts of the kidney from the framework of the organ, or stroma.
The primary structural component of the renal parenchyma are the nephrons. Each human kidney contains about one million nephrons, according to the Encyclopedia Britannica. A nephron is a very thin tube that collects blood and filters out a variety of impurities. This is the process that leads to the creation of urine. In some individuals this process does not function properly. Doctors call this dysfunction renal parenchymal disease, but it is not really a single disease. It is a condition that stems from a variety of other causes, such as polycystic kidney disease, interstitial nephritis and hydronephrosis. These are not the exclusive causes. The symptoms of renal parenchymal disease include the passing of blood through the urine, frequent urination and swelling. The best treatment for renal parenchymal disease depends on the underlying cause. The disease is not curable in most cases. The Mayo Clinic states that treatment often involves the patient making changes in his lifestyle, such as switching to a different diet.