Kidneys have lots of reserve, but getting ahead of small decreases in function prevents later damage.

You often hear older people say I have weak kidneys. That doesn't mean they can't do their job or are destined to fail. But it does indicate you have some form of chronic kidney disease. The kidneys—the body's blood-filtering urine factory—have less capacity to filter toxins from the blood and excrete them in the urine.

Half of U.S. adults over 75 may have below-normal kidney function. Most of them will never get sick from it, unless they have other conditions such as diabetes or uncontrolled hypertension, or take medications that can injure the kidney.

What causes it?

Every day, a healthy kidney filters a total of about 200 quarts of blood, removing waste products, excess water, and certain chemicals. If the kidneys didn't keep things in balance, you would slowly poison yourself.

Read more...