Risk Factors for CKD
When you have a risk factor, it means you are more likely to have a problem than someone who does not have it. But it doesn't mean that you will definitely have the problem.
Some risk factors, like your age or family history, are out of your control. But you can control other risk factors, and perhaps slow down or even prevent some diseases. For instance, keeping your blood pressure and your blood sugar in their target ranges may help your kidneys work longer.
First, know your risk factors for CKD. Then work with your doctor to prevent or delay kidney failure.
Kidney Disease Risk Factors You Can Change
Type 2 diabetes is the number one cause of kidney failure. There's no such thing as "a touch of the sugar". About 44% of new dialysis patients have diabetes.
What you can do: Kidney disease does not have to happen to people with diabetes. Good blood pressure and blood sugar control can help prevent it. Tight control can have big payoffs in reducing the risk for kidney disease. It can also help protect your blood vessels, limbs, and eyes.
High Blood Pressure (Hypertension)
High blood pressure puts extra stress on all of your blood vessels, including your tiny, fragile kidney filters (nephrons). Hypertension is the number two cause of kidney failure.
- Normal blood pressure is less than 130/85—this is the target for the general public.
- If you have diabetes or protein in your urine, the target is 125/75.
Weight control, exercise, and medications can control blood pressure. Keeping your blood pressure in the target range can help prevent or slow the rate of CKD.
What you can do: Take blood pressure pills as they are prescribed so they will work properly. It is not true that you can "feel" high blood pressure—it can have no symptoms at all. If you can't afford your blood pressure pills or they have side effects you can't live with, tell your doctor. He or she can give you samples, switch you to a less costly drug, or suggest other options for you.
Two classes of blood pressure medications can help protect the kidneys, especially if you have protein in your urine. These are:
- Angiotensin-converting enzyme (ACE) inhibitors (generic names end in "pril" - captopril, ramipril, etc.)
- Angiotensin receptor blockers (ARBs) (generic names end in "sartan" - telmisartan, valsartan, losartan, olmisartan, etc.)
If you have high blood pressure and are not taking one of these drugs, ask your doctor if it would be a good choice for you.
Urine can back up into one or both kidneys and cause damage, if:
- You have scars from kidney infections
- You have a birth defect that caused a kink in one or both ureters (the tubes that carry urine from the kidneys to the bladder)
- Blood clots or plaques of cholesterol block your kidneys' blood vessels
- Kidney stones block the flow of urine from the kidney
What you can do: Some blockages can be fixed to help save function in a blocked kidney. Kidney stones can be treated. If you know or think that you may have a blockage, ask your doctor what can be done about it.
Overuse of Painkillers and Allergic Reactions to Antibiotics
Heavy use of non-steroidal anti-inflammatory (NSAID) pain pills has been linked to kidney inflammation that can lead to kidney failure. The problem these drugs can cause is called interstitial nephritis. Watch out for drugs with these ingredients:
- Ibuprofen (Advil®, Motrin®)
- Naproxen (Aleve®)
- Acetaminophen (Tylenol®)
One pill per day is not harmful in men (at least) who are not at risk for kidney disease.
Allergic reactions to—or side effects of—antibiotics like penicillin and vancomycin may also cause nephritis and kidney damage.
What you can do: If you take these drugs each day, be sure that your doctor knows it. This is especially vital if you already have a known kidney problem. When you are taking a new medication, report any new symptoms to your doctor. Just because you can buy something at a drugstore without a prescription does not mean that it's harmless.
Use of recreational drugs can harm the kidneys and may lead to kidney failure and the need for dialysis. These drugs include:
- Cocaine and crack cocaine
- PCP ("angel dust")
What you can do: If you are using these drugs, know that they can harm your health and seek help to stop. Be honest with your doctor about your medical history—he or she can't help you without knowing the full story.
Certain illnesses, like glomerulonephritis (inflamed kidney filters), can damage the kidneys. Sometimes the damage is enough to cause kidney failure. Some glomerulonephritis is passed down in families. Some may be an immune response to infections like strep throat.
What you can do: Know your family history. Having a throat culture for bad sore throats, and treating any strep infection to lower this risk.
X-ray Dye Tests
The dye used for contrast (to make soft tissues show up on X-rays, CT scans, and MRIs) can harm the kidneys. This risk is higher if:
- You already have some kidney damage
- You have congestive heart failure
- You have diabetes
- You are dehydrated before an X-ray test is done
- Your systolic blood pressure (the top number) is 80 or lower
- You are 75 or older
What you can do:
- Talk to your doctor, especially if you have a risk factor. Be sure that an X-ray test with contrast is the only way to find out what he or she needs to know. In some cases, a plain-film X-ray or ultrasound may work as well.
- Ask your doctor about n-acetylcysteine (NAC), an antioxidant that is taken by mouth for a couple of days before a test. In some studies, NAC has helped protect the kidneys from contrast damage.
- Be sure the radiologist knows your kidney status so he or she can take precautions.
- Ask the radiologist if you can have an IV with bicarbonate in it before and during the test. Some studies have shown that this can help protect the kidneys, though other studies did not find it any better than normal saline (salt water).
Kidney Disease Risk Factors You Can't Change But Should Know About
A Family History of Kidney Disease
If you have one or more family members who have CKD, are on dialysis, or have a kidney transplant, you may be at higher risk. One inherited disease, polycystic kidney disease (PKD), causes large, fluid-filled cysts that can crowd out normal kidney tissue. Diabetes and high blood pressure can also run in families. Know your family history and share it with your doctor. This can ensure that you are screened for risk factors and get the care you need.
About one in five very premature infants (less than 32 weeks) may have calcium deposits in the kidney filters (nephrons). This is called nephrocalcinosis. Some people who have this may go on to have kidney problems later in life.
Kidney function declines as we age. The older you are, the greater your risk.
Trauma or Accident
Accidents, injuries, some surgeries, and X-ray dyes can reduce blood flow to the kidneys. This can result in acute (sudden) kidney failure. Some acute kidney failure will get better, but the risk of CKD is much higher if your kidneys have failed before for any reason.
Having certain diseases puts people at higher risk of kidney disease. These include:
- High blood pressure
- Systemic lupus erythematosus (a connective tissue disease)
- Sickle cell anemia
- Hepatitis C
- Congestive heart failure.