What you and your doctor will look for in your checkups and lab work
Blood pressure
High blood pressure, or hypertension, can raise the risk of kidney disease and other ailments, so make sure your health care provider is checking your blood pressure at most regular visits. Blood pressure varies as your heart beats, so doctors measure the highest (systolic) and lowest (diastolic) numbers to capture the overall range. Normal readings are lower than 120/80 mmHg. [Note: mmHg, or millimeters of mercury, are the units of pressure.]
Readings higher than 140/90 (either number) are considered a diagnosis of high blood pressure. Anything in between—a top number from 120 to 139, or 80 to 89 on the bottom—could flag trouble to come and may require some lifestyle adjustments. High blood pressure is more likely to go undiagnosed or untreated in Latinos, so ¡cuídate! Avoid becoming a statistic and get checked.
Blood tests
Excess waste products in the blood can mean the kidneys aren’t clearing them properly. Measuring two such waste chemicals, creatinine and urea, is key to tracking poor kidney function.
Creatinine levels
Creatinine is a chemical released by the normal buildup and breakdown of muscle cells. It can be measured by a simple blood test. Your kidneys should eliminate creatinine as it is produced, keeping levels constant. Definitions of “normal” vary slightly, but are generally between 0.6 and 1.2 mg/dL for men and 0.5 and 1.1 mg/dL for women. Note: The more muscular you are, the higher your “normal” creatinine levels will tend to be. In people taking tenofovir, creatinine levels may occasionally spike but return to normal. Don’t worry about the odd blip. But repeatedly high tests should prompt your doctor to investigate more closely.
GFR/creatinine clearance rate
To better estimate how well your kidneys are working, your doctor can crunch your creatinine level through a few calculations. These equations, called Cockcroft-Gault and MDRD (Modification of Diet in Renal Disease), factor in your age, weight and other factors like sex and race. The results—your creatinine clearance rate and glomular filtration rate (GFR)— describe how quickly your kidneys process creatinine. (The National Kidney Foundation and other experts consider GFR to be the best measurement of kidney function.) Higher numbers are better: A healthy creatinine clearance rate is one higher than 60 mL per minute.
Blood urea nitrogen (BUN) and proteinuria tests
Healthy kidneys dump protein waste products from blood into your urine. The blood urea nitrogen (BUN) test measures how much urea, a waste product from protein breakdown, is still in your blood. Normal adult levels are typically in the 7 to 18 mg/dL range; high levels show that the kidneys aren’t eliminating this waste as much as they should. Healthy kidneys also keep useful protein in the blood. Urine tests can determine whether protein has leaked into the urine, a condition called proteinuria. Abnormal lab results may signal that kidney damage may be occurring. At the first sign of trouble, you should: Get blood sugar and blood pressure under control; make sure you’re not taking kidney-toxic drugs; and possibly have more detailed tests, such as an ultrasound or biopsy.
