What is CRF/CKD (Chronic Renal Failure)?
Chronic kidney disease occurs when one suffers from gradual and usually
permanent loss of kidney function over time. This happens gradually,
usually months to years. The term "renal" refers to the kidney, so
another name for kidney failure is "renal failure." Mild kidney
disease is often called renal insufficiency.
Chronic loss of function causes generalized wasting (shrinking in size) and
progressive scarring within all parts of the kidneys. In time, overall
scarring obscures the site of the initial damage. Yet, it is not until over
70% of the normal combined function of both kidneys is lost that most
patients begin to experience symptoms of kidney failure.
Often, chronic kidney disease is diagnosed as a result of screening of
people known to be at risk of kidney problems, such as those with high blood
pressure or diabetes and those with a blood relative with chronic kidney
disease. Chronic kidney disease may also be identified when it leads to one
of its recognized complications, such as cardiovascular disease, anemia or
pericarditis.
Chronic kidney disease is identified by a blood test for creatinine. Higher
levels of creatinine indicate a falling glomerular filtration rate and as a
result a decreased capability of the kidneys to excrete waste products.
Creatinine levels may be normal in the early stages of CRF, and the
condition is discovered if urinalysis (testing of a urine sample) shows that
the kidney is allowing the loss of protein or red blood cells into the
urine.
Table 1. Stages of Chronic Kidney Disease
| Stage |
Description |
GFR*
mL/min/1.73m2 |
| 1 |
Slight kidney damage with normal or increased filtration |
More than 90 |
| 2 |
Mild decrease in kidney function |
60-89 |
| 3 |
Moderate decrease in kidney function |
30-59 |
| 4 |
Severe decrease in kidney function |
15-29 |
| 5 |
Kidney failure |
Less than 15 (or dialysis) |
*GFR is glomerular filtration rate, a measure of the kidney's
function