The main causes of high creatinine in the blood include glomerulonephritis, pyelonephritis and acute tubular necrosis, which are conditions that affect kidney function, according to LabTestsOnline. Creatinine is a waste product that is filtered by the kidneys, and abnormal levels suggest problems with the kidneys.
Glomerulonephritis refers to a group of diseases that cause injury to the kidneys, notes the National Kidney Foundation. The disease can be both chronic and acute, and patients may not experience any symptoms for a while if the condition is chronic. Patients suffering from the acute form of glomerulonephritis experience facial puffiness, blood in the urine and shortness of breath. The condition is caused by infections or other illnesses, and it is diagnosed through urine and blood tests as well as kidney biopsies.
Pyelonephritis is a urinary tract infection that occurs when a bacterium or virus infects the kidneys, according to the National Institute of Diabetes and Digestive and Kidney Disorders. Symptoms of the condition include fever, chills, back pain and painful urination. Pyelonephritis is diagnosed through various tests, including urine samples, ultrasound and CT scans.
Acute tubular necrosis occurs when the tubule cells of the kidneys are damaged, explains MedlinePlus. The disease is typically caused by insufficient oxygen in the kidneys, which sometimes occurs in hospitalized patients receiving blood transfusions or who have had major surgery. Patients with acute tubular necrosis experience nausea, vomiting, drowsiness and fluid retention. Doctors diagnose the condition by performing a physical exam to check for excess fluid in the body and by ordering blood and urine tests.