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Definition, causes and symptoms of chronic kidney disease

Healthy kidneys function to remove extra water and waste from the blood, help control blood pressure, keep body chemicals in balance, keep bones strong, tell your body to make red blood cells and help children grow normally. Chronic kidney disease (CKD) occurs when kidneys are no longer able to clean toxins and waste product from the blood and perform their functions to full capacity. This can happen suddenly or over time.

"Renal" means related to the kidneys. "Acute" means sudden. So acute renal failure means the kidneys have failed suddenly, often due to a toxin (a drug allergy or poison) or severe blood loss or trauma. Dialysis is used to clean the blood and give the kidneys a rest. If the cause is treated, the kidneys may be able to recover some or all of their function.

Diabetes is the number one cause of kidney disease, responsible for about 40 percent of all kidney failure. High blood pressure is the second cause, responsible for about 25 percent. Another form of kidney disease is glomerulonephritis, a general term for many types of kidney inflammation. Genetic diseases, autoimmune diseases, birth defects and other problems can also cause kidney disease.

Diabetes is a risk factor for kidney disease, but this does not mean your kidneys will fail. You can care for your kidneys by controlling your blood sugar and getting regular microalbumin urine tests to catch any early signs that your diabetes may be affecting your kidneys. Even if you develop diabetic kidney disease, you can work with your doctor to keep your kidneys functioning as long as possible.

No. Kidney disease is not contagious. You cannot catch it from someone. Most kidney disease is caused by diabetes and high blood pressure, conditions that can run in families. If you are a family member of someone who has diabetes, high blood pressure or kidney disease, it is a good idea to ask your doctor to check your blood pressure and kidney function at your checkup.

A kidney stone occurs when substances in the urine form crystals. Kidney stones can be large or small. Large ones can damage the kidneys; small ones may be able to pass in the urine. Because crystals have sharp edges, passing even small stones can be very painful. Treatment depends on what the stones are made of.

Parathyroid hormone (PTH) is produced by several small, bean-like parathyroid glands in your neck. Its "job" is to tell your bones to release calcium into your bloodstream. Too much PTH can become a problem in people with kidney disease.

Healthy kidneys convert a hormone called calcitriol to its active form of vitamin D. Calcitriol lets your body absorb calcium from food you eat. When your kidneys are not working well, they start to make less calcitriol – so even if you eat calcium, your body can't absorb it. PTH kicks in to make sure you always have enough calcium in your blood. Over time, this can weaken your bones.

A blood test can show if your PTH levels are above normal. If they are, your doctor may prescribe a form of active vitamin D.

Since 60-70 percent of people with PKD have a family member with PKD, asking your doctor about being tested is a good idea. The first test used for PKD is an ultrasound to look at the kidneys and see if there are cysts. This is a non-invasive test. Learning more about PKD may help you to take better care of your kidney health. The PKD Foundation has free information that can help you. You can learn more at 1-800-PKD-CURE or by visiting their website (http://www.pkdcure.org).

Knowing the symptoms of kidney disease can help people detect it early enough to get treatment. Symptoms can include:

• Changes in urination—making more or less urine than usual, feeling pressure when urinating, changes in the color of urine, foamy or bubbly urine, or having to get up at night to urinate.
• Swelling of the feet, ankles, hands, or face—caused by fluid the kidneys can't remove which may stay in the tissue.
• Fatigue or weakness—caused by a build-up of waste or a shortage of red blood cells (anemia) when the kidneys begin to fail.
• Shortness of breath—caused by fluid building up in the lungs; for this reason, kidney failure is sometimes confused with asthma or heart failure.
• Ammonia breath or an ammonia or metal taste in the mouth—a result of waste build-up in the body that can cause bad breath, changes in taste, or an aversion to protein foods like meat.
• Back or flank pain—affecting the area where the kidneys are located on either side of the spine in the back.
• Itching—may be severe, especially in the legs, as a result of waste build-up in the body.
• Loss of appetite
• Nausea and vomiting
• More hypoglycemic episodes (if diabetic)

If you believe you have any of these symptoms, talk to your doctor about your concerns. This is especially important if you have a close family member who has kidney disease, or if you have diabetes or high blood pressure, which are the main causes of kidney failure.

Your physician can diagnose kidney disease by conducting lab tests and by assessing your symptoms. High blood levels of creatinine and urea nitrogen (BUN) or high levels of protein in your urine suggest kidney disease. Diabetics should have a yearly urine test for microalbumin, small amounts of protein that don't show up on standard urine protein test.

Causes of kidney disease

Some people get chronic kidney disease because of genetics… READ MORE »