Creatinine is produced by creatine which is an important molecule for energy production in muscles. It is a waste product generated by muscle activity that it released into the blood stream. Creatinine level is an important assessment tool for doctors.

High level of craetinine can be caused by many reasons, main one being a kidney disease. But the creatinine levels do not start to rise till about 40 percent of kidney has stopped functioning.Dehydration can also be a cause of high level of creatinine. Transient or temporary high level of creatinine can also be caused by hardening of the arteries. High creatinine levels are also seen after a heart surgery.