KIDNEYS DISORDERS

There are many forms of kidneys diseases. Many of the following abnormalities have no symptoms and may often go undetected, at least initially, or are detected when tests are done.

Glomerulonephritisresults from inflammation of the filtration membrane within the renal corpuscle. It is characterized by an increased permeability of the filtration membrane and the accumulation of numerous white blood cells in the area of the filtration membrane. As a consequence, a high concentration of plasma proteins enters the urine along with numerous white blood cells. Plasma proteins in the filtrate increase the osmolality of the filtrate, causing a greater-than-normal urine volume. The signs and symptoms are the following: cola- or tea-colored urine, hypertension, fluid retention, headaches, blurred vision, and generalized aches.

Pyelonephritis is inflammation of the renal pelvis, medulla, and cortex. It often begins as a bacterial infection of the renal pelvis and then extends into the kidney itself. It can result from several types of bacteria. Pyelonephritis may cause the destruction of nephrons and renal corpuscles, but because the infection starts in the pelvis of the kidney, it affects the medulla more than the cortex. As a consequence, the ability of the kidney to concentrate urine is dramatically affected. As a rule the person has flank pain, high fever, vomiting, and burning sensation during urination. When properly treated, acute pyelonephritis rarely progresses to chronic renal disease, although it can be an immediate threat to life in an elderly or weakened persons. It can also recur if the infection is not totally eradicated.

Renal failure may result from any condition that interferes with kidney function. Acute renal failure occurs when damage to the kidney is extensive and leads to the accumulation of the urea in the blood and to acidosis. In complete renal failure death may occur in 1 to 2 weeks. Acute renal failure may result from acute glomerulonephritis, or it may be caused by damage to or blockage of renal tubules. Some poisons such as mercuric ions or carbon tetrachloride that are the common to certain industrial processes cause necrosis of the nephron epithelium. If the damage does not interrupt the basement membrane surrounding the nephrons, extensive regeneration can occur within 2 or 3 weeks. Severe ischemia associated with circulatory shock caused by sympathetic vasoconstriction of the renal blood vessels can cause necrosis of the epithelial cells of the nephron.