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...ns may happen quickly, often as the result of injury or poisoning. But most kidney diseases destroy the nephrons slowly and silently. Only after years or even decades will the damage become apparent. Most kidney diseases attack both kidneys simultaneously. The two most common causes of kidney disease are diabetes and high blood pressure. Diabetic Nephropathy Diabetes is a disease that keeps the body from using glucose (sugar) as it should. If glucose stays in your blood instead of breaking down, it can act like a poison. Damage to the nephrons from unused glucose in the blood is called diabetic nephropathy. If you keep your blood glucose levels down, you can delay or prevent diabetic nephropathy. High Blood Pressure High blood pressure can damage the small blood vessels in your kidneys. The damaged vessels cannot filter wastes from your blood as they are supposed to. Inherited and Congenital Kidney Diseases Some kidney diseases result from hereditary factors. Polycystic kidney disease (PKD), for example, is a genetic disorder in which many cysts grow in the kidneys. PKD cysts can slowly replace much of the mass of the kidneys, reducing kidney function and leading to kidney failure. Some kidney problems may show up when a child is still developing in the womb. Examples include autosomal recessive PKD, a rare form of PKD, and other developmental problems that interfere with the normal formation of the nephrons. Microalbuminuria and Proteinuria Healthy kidneys take wastes out of the blood but leave protein. Impaired kidneys may fail to separate a blood protein called albumin from the wastes. At first, only small amounts of albumin may leak into the urine, a condition known as microalbuminuria, a sign of deteriorating kidney function. As kidney function worsens, the amount of albumin and other proteins in the urine increases, and the condition is called proteinuria. As blood passes through healthy kidneys, they filter the waste products out and leave in the things the body needs, like proteins. Most proteins are too big to pass through the kidneys' filters into the urine unless the kidneys are damaged. The main protein that is most likely to appear in urine is albumin. Proteins form the blood can escape into the urine when the filters of the kidney, called glomeruli, are damaged. Sometimes the term albuminuria is used when a urine test detects albumin specifically. Albumin's function in the body includes retention of fluid in the blood. It acts like a sponge, soaking up fluid from body tissues. Renal osteodystrophy is a bone disease that occurs when your kidneys fail to maintain the proper levels of calcium and phosphorus in your blood. It's a common problem in people with kidney disease and affects 90 percent of dialysis patients.The bone changes from renal osteodystrophy can begin many years before symptoms appear in adults with kidney disease. For this reason, it's called the "silent crippler." The symptoms of renal osteodystrophy aren't usually seen in adults until they have been on dialysis for several yers.Hematuria is the presence of red blood cells (RBCs) in the urine. In microscopic hematuria, the urine appears normal to the naked eye, but examination under a microscope shows a high number of RBCs. Gross hematuria can be seen with the naked eye—the urine is red or the color of cola. The glomerulus is the main filter of the nephron and is located within the Bowman's capsule. The glomerulus resembles a twisted mass of tiny tubes through which the blood passes. The glomerulus is semipermeable, allowing water and soluble wastes to pass through and be excreted out of the Bowman's capsule as urine. The filtered blood passes out of the glomerulus into the efferent arteriole to be returned through the medullary plexus to the intralobular vein. Bowman's Capsule The Bowman's capsule contains the primary filtering device of the nephron, the glomerulus. Blood is transported into the Bowman's capsule from the afferent arteriole (branching off of the interlobular artery). Within the capsule, the blood is filtered through the glomerulus and then passes out via the efferent arteriole. Meanwhile, the filtered water and aqueous wastes are passed out of the Bowman's capsule into the proximal convoluted tubule. In humans the kidneys are two organs located in the posterior part of the abdomen. There is one on each side of the spine just below the liver and spleen. Superior to each kidney is an adrenal gland (also called the suprarenal gland). The kidneys are retroperitoneal, which means they lie behind the peritoneum, the lining of the abdominal cavity. They are approximately at the vertebral level T12 to L3, and the right kidney usually lies slightly lower than the left in order to accommodate the liver. The upper parts of the kidneys are partially protected by the eleventh and twelfth ribs, and each whole kidney is surrounded by two layers of fat (the perirenal fat and the pararenal fat) which help to cushion it. The outermost portion of the kidney is called the renal cortex, deep to which lies the renal medulla. The innermost portion is the pelvis. The renal pyramids, which are actually openings of the collecting ducts, can be observed in the human renal medulla. The outside is cove...