What Are the Kidneys?
Your kidneys are located near the back of your torso, about even with the lowest ribs. One kidney is on either side of the spine. Their main job is to clean the blood of waste products created when your body burns fuel. But they also perform other tasks. For example, they help regulate the amount of fluid in your body. If you were to drink five quarts of fluid one day and just a pint the next, your kidneys would keep your body's water levels in balance despite the vast differences in intake.

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Your kidneys are part of a body system called the urinary tract. They receive blood from the heart through the renal artery, filter it, and send the waste out to the bladder, where it is stored until urination. The kidneys produce only about a quart of urine per day. This is not a large amount, but it's crucial to your health. If the kidneys fail for some reason, toxins build up and cause death unless you receive either a kidney transplant or a medical treatment called dialysis to cleanse the blood.

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Treating problems
Most kidney problems are readily treatable. Kidney infections can be treated with antibiotics. Kidney stones develop when the kidneys fail to process protein properly or when high amounts of certain minerals accumulate in the urine. Kidney stones can be passed on their own, removed in surgery or through a scope, or pulverized by special shock wave machines.
Kidneys can be damaged by chronic conditions such as diabetes or hypertension and gradually lose function until they reach a condition called end-stage renal disease (ESRD). Certain hereditary diseases, such as polycystic kidney disease, may cause ESRD early in childhood or adolescence. ESRD is an extremely serious condition and can lead to death.
Diabetes, which damages blood vessels in the kidney, is the chief cause of kidney failure. Hypertension, or high blood pressure, is a close second. Together, they are responsible for about 70 percent of kidney disease leading to dialysis or kidney transplant.
Kidney health
A healthy lifestyle—eating sensibly, staying trim, exercising, and avoiding excessive alcohol—may help control high blood pressure. In addition, it may prevent or delay the onset of type 2 diabetes. If you have diabetes, it is important that you maintain a normal blood sugar (less than 120) or a hemoglobin A1C level of seven or less, and a blood pressure less than 130/80. In addition to a healthy lifestyle, you should follow your health care provider's recommendations and take appropriate diabetic medications, including those to control blood sugar, ACE inhibitors to protect your kidneys, and insulin, if necessary. Good diabetic control and a healthy lifestyle will help you maintain healthy kidneys throughout your lifetime. Women with hypertension who are pregnant should not take ACE inhibitors; women with hypertension who are planning to become pregnant and who take ACE inhibitors should talk with their doctor about changing blood pressure medication before becoming pregnant.