causes+of+kidney+failure

"Your kidneys are two bean-shaped organs, each about the size of your fist. They're located at the back of your upper abdomen, one on either side of your spine. Your kidneys are part of a system that removes excess fluid and waste material from your blood. Initially, blood enter your kidneys through the renal arteries, which are branches of the aorta - the main artery carrying oxygenated blood from your heart to the rest of your body. From there, blood moves through structures in your kidneys known as nephrons. Causes of acute kidney failure are generally categorized in relation to where and how they affect your kidneys:
 * **Prerenal.** These are problems that interfere with the flow of blood on its way to your kidneys.
 * **Renal.** These are causes that result in direct damage to your kidneys
 * **Postrenal.** These are problems with the flow of urine after it leaves the kidneys on its way out of your body

Prerenal problems are among the most common causes of acute kidey failure. Examples of problems that may leave your kidneys with an insufficient blood supply to function properly include: Conditions that may affect the structure and function of the kidney itself, potentially leading to acute kidney failure, include: Atheroembolic kidney disease can occur when masses of cholesterol and cellular debris (plaques) accumulate in arteries and harden in a process called atherosclerosis. If a plaque is injured or disturbed — cardiac catheterization, a procedure used to conduct diagnostic tests and treatments on the heart, is a common cause — pieces of it may break off into your bloodstream and move throughout your body. These moving pieces are called emboli. When these emboli move to your kidneys, the cholesterol emboli accumulate in small blood vessels (arterioles). Within the arterioles, these emboli can produce severe inflammation, leading to decreased blood supply and acute kidney failure. Other causes of reduced blood supply include a blood disorder called idiopathic thrombocytopenic purpura, development of blood clots in kidney vessels, a reaction to a blood transfusion, or a sudden onset of severe high blood pressure (malignant hypertension). Acute glomerulonephritis may be associated with immune diseases, such as lupus or IgA nephropathy (Berger's disease). It may also follow an infection in another part of your body, such as strep throat, infection of a heart valve (endocarditis), typhoid fever, syphilis and malaria. Viruses that cause AIDS, mononucleosis, mumps, measles or hepatitis also may trigger glomerulonephritis. Postrenal causes of acute kidney failure are generally related to obstruction of the flow of urine out of your kidneys on the way out of your body. This may occur at the level of the tubes that lead from your kidneys to your bladder (ureters), or at the bladder level (urethral obstruction).
 * Prerenal**
 * **Extremely low blood pressure.** Severe bleeding, infection in the bloodstream (sepsis), dehydration or shock can all lead to a drastic drop in blood pressure that prevents an adequate amount of blood from reaching your kidneys. These conditions tend to occur after a traumatic injury or as a risk of major surgery.
 * **Poor heart function.** If your heart isn't functioning at full capacity, such as during a heart attack or with congestive heart failure, the result can be reduced blood flow to your kidneys.
 * **Low blood volume.** Severe dehydration — which can be brought on by prolonged vomiting or diarrhea, heatstroke or major burns — results in excessive loss of fluid, diminishing the volume of blood in your body and the amount available to your kidneys.
 * Renal**
 * Disorders that reduce blood supply in your kidneys.** Any number of disorders can lead to decreased blood supply in your kidneys, which can lead to organ damage and acute kidney failure. One example is atheroembolic kidney disease.
 * Disorders that reduce blood supply in your kidneys.** Any number of disorders can lead to decreased blood supply in your kidneys, which can lead to organ damage and acute kidney failure. One example is atheroembolic kidney disease.
 * **Hemolytic uremic syndrome.** This condition, which is associated with certain strains of Escherichia coli (E. coli) bacteria, is a leading cause of acute kidney failure in infants and young children. The bacterium causes inflammation of the intestine. It also produces a toxin that causes damage and swelling in the lining of blood vessels, especially the small blood vessels (glomerular capillaries) in the kidneys. As red blood cells travel through the damaged blood vessels, they're often broken apart (hemolysis). This complex condition may result in acute kidney failure.
 * Inflammation in the kidneys.** Acute kidney failure may result from sudden inflammation of the spaces between the glomeruli and the tubules (acute interstitial nephritis) and inflammation of the glomeruli (acute glomerulonephritis). Acute interstitial nephritis is usually associated with an allergic reaction to a drug. Examples include certain antibiotics — especially streptomycin or gentamicin — and common pain medications, such as aspirin and ibuprofen (Advil, Motrin, others). Antibiotics pose a greater risk of acute kidney failure for people who already have liver or kidney disease or who use diuretics or other drugs that affect your kidneys.
 * Inflammation in the kidneys.** Acute kidney failure may result from sudden inflammation of the spaces between the glomeruli and the tubules (acute interstitial nephritis) and inflammation of the glomeruli (acute glomerulonephritis). Acute interstitial nephritis is usually associated with an allergic reaction to a drug. Examples include certain antibiotics — especially streptomycin or gentamicin — and common pain medications, such as aspirin and ibuprofen (Advil, Motrin, others). Antibiotics pose a greater risk of acute kidney failure for people who already have liver or kidney disease or who use diuretics or other drugs that affect your kidneys.
 * **Toxic injury.** Because the main purpose of your kidneys is to filter toxins from your body, your kidneys are particularly vulnerable to toxic injury. Exposure to toxic substances — such as excessive amounts of alcohol, cocaine, heavy metals, solvents and fuels — can induce acute kidney failure. Certain drugs also have the potential to injure the tubules in your kidneys, including chemotherapy drugs and contrast dyes used in medical tests, such as arteriography. Contrast dyes are a common cause of acute renal failure, especially in people with diabetic kidney disease or multiple myeloma, a type of cancer.
 * Postrenal**
 * **Ureter obstruction.** Kidney stones in both ureters (or in a single ureter if only one kidney is functioning) or tumors pushing in on the ureters can cause obstruction at this level.
 * **Bladder obstruction.** In the bladder, the most common cause of obstruction in men is an enlarged prostate, which causes obstruction at the bladder outlet. Other obstructive bladder causes, in both men and women, include a bladder stone, blood clot, tumor or a nerve disorder that prevents the bladder from contracting properly.


 * all information from http://www.mayoclinic.com/health/kidney-failure/DS00280 **