In its earliest stages, microalbuminuria may come and go. But as the rate of albumin loss increases from 20 to 200 micrograms per minute, microalbuminuria becomes more constant. A special test is required to detect microalbuminuria. The loss of albumin and other proteins in the urine exceeds 200 micrograms per minute. It now can be detected during routine urine tests.
Some patients develop high blood pressure.
The glomeruli suffer increased damage. The kidneys progressively lose the ability to filter waste, and blood levels of creatinine and urea-nitrogen rise. People with either type of diabetes may remain at stage III for many years. The glomerular filtration rate decreases to less than 75 milliliters per minute, large amounts of protein pass into the urine, and high blood pressure almost always occurs. Levels of creatinine and urea-nitrogen in the blood rise further.