How Many Stages for Kidney Function Decrease?

The kidney function decrease caused by chronic kidney disease can be classified into 4 stages:
Stage I: the stage of kidney reserve decrease: in clinical, this stage is also called kidney insufficiency compensatory stage. At this stage, the renal nephrons will decrease by 20%-50%; the renal excretion and regulatory function are still normal; blood urea nitrogen and serum creatinine are also in the normal range; and patients commonly have no symptoms;

Stage II kidney insufficiency decompensatory stage: the renal nephrons decrease by 50%-70%, the renal excretion and regulatory function are decreasing; patients appear urination increase in the night, fatigue, nausea, vomitting, diarrhea, anemia and such symptoms; the renal concentration is a little poor; blood urea nitrogen and serum creatinine begin to increase, and patients may have slight acidosis. At this stage, the treatment should be primary with non-dialysis treatment.
Stage III kidney failure stage, also called preuremic stage, the renal nephrons decrease by 75%-90%; patients appear the symptoms of urination increase at night, severe anemia and uremic systemic symptoms, and patients may also have hypocalcemia, hyperphosphatemia, hyperchloremia and hyponatremia. The metabolic acidosis is obvious. At this stage, patients should prepare to do dialysis and rectify anemia;

Stage IV, end-stage uremia: the renal nephrons is less than 10%, patients appear the severe systemic poisoning symptoms and complications, including, digestive system, cardiovascular system, nervous system and so on. Patients may also appear secondary hyperparathyroidism. At this time, patients should take dialysis to maintain life.