What causes high urea nitrogen creatinine?

High urea nitrogen creatinine generally indicates impaired renal function. Patients with impaired renal function due to renal filtration function decline, resulting in blood urea nitrogen and creatinine can not be discharged in time will cause blood urea nitrogen creatinine elevation, common reasons are as follows: First, prerenal lesions, such as massive blood loss, fluid loss or shock patients, due to the reduction of blood through the kidneys, so will show acute renal failure. Second, kidney disease, more common glomerulonephritis, IGA nephropathy, nephrotic syndrome or diabetic nephropathy. Third, renal disease, more common prostatic hyperplasia, urinary tract stones.