Your kidneys have a pretty important job: they remove waste products and extra water from your body. And they work pretty hard, too. In a minute, a healthy kidney filters about a half a cup of fluid (between 88 and 137 milliliters) — that makes for some 200 quarts of liquid filtered every day.
Kidney disease means that your kidneys have been damaged and can no longer perform their usual functions. It can develop for a variety of reasons, and may be mild or severe.
There are several stages of kidney disease; the early stages may have few or no symptoms. One of the earliest signs of kidney disease is the level of a protein called albumin in urine.
- Stage One: Normoalbuminuria — Urinary protein loss is normal. Blood flow through the kidneys may increase (hyperfiltration). The kidneys may be enlarged (hypertrophy).
- Stage Two: Microalbuminuria — Urinary protein levels can be high at random. Exercise, blood sugar levels, blood pressure, and infection can affect your albumin levels; to make a diagnosis, your doctor will need three or more urine samples.
- Stage Three: Macroalbuminuria — Consistently high protein levels in urine. High blood pressure may become an issue, if not already a health issue.
- Stage Four: Later-Stage Kidney Disease — Protein levels in urine continue to increase. Kidney filtration rate drops to less than 75 milliliters per minute.
- Stage Five: End-Stage Kidney Disease — Kidney filtration rate drops to less than 10 milliliters per minute. Blood filtering must be done by dialysis or a transplanted kidney.
As many as thirty percent of people with diabetes end up developing kidney disease. Other risk factors include smoking, high blood pressure, high blood sugar levels, high protein diets, and race — African-American, Asian-American, and Native American people tend to be at higher risk for kidney disease.
Take a look at at-home blood testing.