Clinical evaluation of renal function reveals a decrease in glomerular filtration rate, mainly due to some specific etiologies that lead to impairment of renal function and the development of this condition of chronic renal insufficiency. Common causes include hypertension, diabetes mellitus, and hematologic disorders, immune dysfunction, and the use of certain medications. Others are seen in hematologic tumors, such as multiple myeloma, which can lead to a decrease in glomerular filtration rate. When this occurs, different levels of differentiation should be made that can be divided into pre-renal, renal and post-renal factors. Pre-renal factors are mainly due to insufficient blood perfusion, reduced water intake and effective circulating blood volume, such as heart failure or hemorrhagic diseases or trauma, which can lead to a decrease in glomerular filtration rate. Renal factors, mainly substantial changes in the kidneys, can lead to a decrease in glomerular filtration rate after the appearance of kidney disease. Post-renal factors are mainly seen in obstruction of the urinary system, such as ureteral stenosis, stones, or fluid retention in the urinary system caused by chronic prostatic hyperplasia in older men, which can lead to a decrease in glomerular filtration rate. Therefore, when you find this kind of condition clinically, you should rule out different factors so as to carry out effective treatment.