Your Kidneys and How They Work
How Do Kidneys Fail?
Many factors that influence the speed of kidney failure are not completely understood. Researchers are still studying how protein in the diet and cholesterol levels in the blood affect kidney function.
Acute Renal Failure
Some kidney problems happen quickly, like an accident that injures the kidneys. Losing a lot of blood can cause sudden kidney failure. Some drugs or poisons can make your kidneys stop working. These sudden drops in kidney function are called acute renal failure (ARF).
ARF may lead to permanent loss of kidney function. But if your kidneys are not seriously damaged, acute renal failure may be reversed.
Chronic Renal Failure
Most kidney problems, however, happen slowly. You may have "silent" kidney disease for years. Gradual loss of kidney function is called chronic renal failure or chronic renal disease.
End-Stage Renal Disease
The condition of total or nearly total and permanent kidney failure is called end-stage renal disease (ESRD). People with ESRD must undergo dialysis or transplantation to stay alive.
What Are the Signs of Kidney Disease?
People in the early stages of kidney disease may not feel sick at all. The first signs that you are sick may be general: frequent headaches or feeling tired or itchy all over your body.
If your kidney disease gets worse, you may need to urinate more often or less often. You may lose your appetite or experience nausea and vomiting. Your hands or feet may swell or feel numb. You may get drowsy or have trouble concentrating. Your skin may darken. You may have muscle cramps.
How Will My Doctor Detect Kidney Disease?
First, your doctor will probably send blood and urine samples to a lab to test for substances that should not be there. If the blood contains too much creatinine or urea nitrogen and the urine contains protein, your kidneys may not be functioning properly.
Creatinine is a waste product in the blood created by the normal breakdown of muscle during activity. Healthy kidneys take creatinine out of the blood and put it in the urine to leave the body. When kidneys are not working well, creatinine builds up in the blood.