Most kidney diseases attack the nephrons, causing them to lose their filtering capacity. Damage to the nephrons 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. If your family has a history of any kind of kidney problems, you may be at risk for kidney disease.
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.
Your doctor may prescribe blood pressure medication. Blood pressure medicines called angiotensin-converting enzyme (ACE) inhibitors and angiotensin receptor blockers (ARBs) have been found to protect the kidneys even more than other medicines that lower blood pressure to similar levels.
The National Heart, Lung, and Blood Institute (NHLBI), one of the National Institutes of Health, recommends that people with diabetes or reduced kidney function should keep their blood pressure below 130/80 mm Hg.
Several different types of kidney disease are grouped together under this category, including autoimmune diseases, infection-related diseases and sclerotic diseases. As the name indicates, glomerular diseases attack the tiny blood vessels (glomeruli) within the kidney.
The most common primary glomerular diseases include membranous nephropathy, IgA nephropathy and focal segmental glomerulosclerosis. Protein, blood, or both in the urine are often the first signs of these diseases. They can slowly destroy kidney function. Blood pressure control is important with any kidney disease.
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. The signs of kidney disease in children vary. A child may grow unusually slowly, may vomit often, or may have back or side pain. Some kidney diseases may be “silent” for months or even years.
If your child has a kidney disease, your child’s doctor should find it during a regular checkup. Be sure your child sees a doctor regularly. The first sign of a kidney problem may be high blood pressure, a low number of red blood cells (anemia), or blood or protein in the child’s urine.
If the doctor finds any of these problems, further tests may be necessary, including additional blood and urine tests or radiology studies. In some cases, the doctor may need to perform a biopsy — removing a tiny piece of the kidney to examine under a microscope.
Some hereditary kidney diseases may not be detected until adulthood. The most common form of PKD was once called "adult PKD" because the symptoms of high blood pressure and renal failure usually do not occur until patients are in their 20s or 30s. But with advances in diagnostic imaging technology, doctors have found cysts in children and adolescents before any symptoms appear.
Other Causes of Kidney Disease
Poisons and trauma, such as a direct and forceful blow to your kidneys, can lead to kidney disease. Some over-the-counter medicines can be poisonous to your kidneys if taken regularly over a long period of time. Products that combine aspirin, acetaminophen, and other medicines such as ibuprofen have been found to be the most dangerous to the kidneys.
If you take painkillers regularly, check with your doctor to make sure you are not putting your kidneys at risk.
The above information is from the National Kidney and Urologic Diseases Information Clearinghouse (NKUDIC), a service of the National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK). The NIDDK is part of the National Institutes of Health of the U.S. Department of Health and Human Services. Publications produced by the Clearinghouse are carefully reviewed by both NIDDK scientists and outside experts.