Hello - thanks for asking your question.
An elevated creatinine is indicative of kidney disease. There are plenty of reasons that can cause kindey disease - I will list some of them here. A creatinine level that high needs to be evaluated, and a 24-hr urine protein and ultrasound are reasonable next steps.
The causes of renal failure is vast. Some examples include medications (i.e NSAIDs, or cyclosporine), heart failure, cirrhosis, hypertension, glomerular disease (i.e. diseases of the kidneys), kidney toxins, infections, automimmune diseases, or renal vascular disease.
I strongly suggest continued followup with your personal physician.
I stress that this answer is not intended as and does not substitute for medical advice - please see your personal physician for further evaluation of your individual case.
Thanks,
Kevin, M.D.