Renal function tests include blood creatinine, blood urea nitrogen, blood and urine β2 microglobulin, and urine albumin. Kidney function abnormalities are mostly seen in kidney diseases, which are divided into primary and secondary. Primary includes chronic nephritis; secondary includes diabetic nephropathy, hypertensive nephropathy and so on. 1. Primary: including chronic nephritis. Chronic nephritis has proteinuria, hematuria, edema and hypertension as the main clinical manifestations, and the condition is prolonged, accompanied by renal insufficiency. 2. Secondary: including diabetic nephropathy, hypertensive nephropathy and so on. Long-term hypertension can lead to increased intraglomerular pressure in the glomerular capsule, renal arteriosclerosis, glomerular fibrosis, atrophy, etc., which can cause renal insufficiency; diabetic nephropathy is one of the most common microvascular complications of diabetes mellitus, and the progression of the disease can lead to renal insufficiency, i.e., the elevation of blood creatinine and urea nitrogen. Patients with abnormal renal function should go to the hospital for consultation, clear diagnosis under the guidance of professional physicians, and timely treatment to avoid delaying the condition.