Final answer:
Renal insufficiency occurs when there is extensive damage to nephrons in the kidney, impairing their ability to function effectively. Chronic kidney disease can lead to permanent kidney failure and may require dialysis.
Step-by-step explanation:
Renal insufficiency occurs when there is extensive damage to nephrons in the kidney, impairing their ability to function effectively. This condition can lead to a decline in kidney function, resulting in a build-up of toxic waste substances in the blood. Renal insufficiency can be classified as either acute renal failure or chronic kidney disease, depending on the trend in serum creatinine levels. Chronic kidney disease can lead to permanent kidney failure and may require dialysis.