Top Tests for Kidney Disease Screening
Kidney disease may not present with symptoms during its early stages. In fact, your doctor may first detect that your have the condition when he or she performs a routine blood or urine test. There are simple tests that your doctor can use to detect if you have kidney disease. The National Kidney Foundation recommends the three simple tests to screen for kidney disease. It include blood pressure checking, spot checking fr protein or albumin in the urine, and calculating glomerular filtration rate (GFR) based on serum creatinine measurement.
Blood Pressure Measurement
Studies have established that uncontrolled high blood pressure can lead to the development of kidney disease. In some cases, it may already be a sign that kidney damage has already occurred.
The best way to know whether your blood pressure is too high or within normal range is to have it checked by your health care provider. Having a very high blood pressure can lead to many complications including stroke, heart attack, or kidney disease.
The National Heart, Lung and Blood Institute (NHLBI) recommends that people who have been diagnosed with kidney disease should try to keep their blood pressure below 130/80 and use whatever therapy is necessary, including lifestyle changes and medications.
Microalbuminuria and Proteinuria
Normally, your kidneys take out wastes from your blood but leave out protein, called albumin. If your kidneys are damaged, albumin may leak and become a part of your urine. This condition is called microalbuminuria, which can be a sign degenerating kidney function. As it worsens, albumin and other proteins in the blood leak out causing proteinuria.
A simple test that your doctor can do to test for protein is using a dipstick in a sample of your urine. The doctor can easily do this in his or her clinic during your visit. The color of the dipstick can tell your doctor whether protein is absent or present.
Glomerular Filtration Rate (GFR) Based on Creatinine Measurement
GFR is a measure of how effective the kidneys are filtering waste products from the blood. In the past, GFR calculation involves injection of a substance into the bloodstream, which is later on measured in a 24-hour urine collection. Now, scientist have found a new way of calculating GFR without injecting agents or collecting urine samples. The procedure, called eGFR, involves measuring of creatinine levels from a small sample of your blood. Creatinine is a waste product in the blood created by the normal breakdown of muscle cells during activity.
Normal range for blood creatinine levels may vary from laboratory to laboratory, but usually ranges from 0.6 to 1.2 mg/dL (milligrams of creatinine per one deciliter of blood). If your level is slightly above the range, you may not feel sick. However, this slight variation may indicate that your kidneys are not working at full strength as they should.
According to the National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK), a creatinine level of 1.7 mg/dL for most men and 1.4 mg/dL for most women equates to 50 percent of normal kidney function.
The NIDDK website says, “The eGFR calculation uses the patient’s creatinine measurement along with age and values assigned for sex and race. Some medical laboratories may make the eGFR calculation when a creatinine value is measured and include it on the lab report.”
Different stages of chronic kidney disease (CKD) can be determined based on the calculated eGFR. When the calculated eGFR is less than 15 milliliters per minute (mL/min), dialysis or kidney transplantation is necessary to sustain life.
National Institute of Diabetes and Digestive and Kidney Diseases. The Kidneys and How They Work. Accessed at http://kidney.niddk.nih.gov/Kudiseases/pubs/yourkidneys/ on September 20, 2010.
National Kidney Foundation. Glomerular Filtration Rate (GFR). Accessed at http://www.kidney.org/kidneydisease/ckd/knowgfr.cfm on September 20, 2010.