Normal bloodcreatinine levels vary and depend on age, race, gender, and body size.Discover what normal creatinine levels are, what it means to have high or lowcreatinine, what a BUN bloodtest is, and how to stay within normal creatinine range. Lowcreatinine levels from a urine or bloodtest give providers clues about muscle and kidney health. Learn why levels go down and what you should do. The prognosis for high or lowcreatininebloodtest levels depends on the cause. Lowcreatinine is often found in people who have lost muscle mass or who have low muscle mass. Creatininetests evaluate kidney function. Read on to learn about high & low levels and how to improve them. A serum creatininetest involves getting a bloodtest. You have a needle inserted into a vein in your arm and a sample of blood is taken. For a urine test, you provide a single sample of urine in the clinic. Or you collect samples at home over 24 hours and return them to the clinic. Typically, creatinine travels in the blood to the kidneys, where it leaves the body in the urine. High levels in the blood might indicate that the kidneys are not working correctly, while low levels can occur with low muscle mass. The creatininebloodtest helps doctors diagnose kidney disease. The creatininebloodtest measures the level of creatinine in the blood. This test is done to see how well your kidneys are working. Learn more about this test. A creatinine clearance test measures GFR by examining creatinine levels in your urine over 24 hours. Lower results in your age range might indicate poorly functioning kidneys or decreased blood flow to them. Creatinine and Kidney Function. Abnormally high amounts of creatinine in the bloodstream and lowcreatininebloodtest levels in the urine at the same time might suggest inadequate excretion. This might indicate a renal disease or another problem interfering with normal kidney functioning. Understanding your creatinine levels is important for monitoring kidney function. Learn more about normal, high and low levels of creatinine, when to worry about your creatine levels and what to do about them. The eGFR bloodtest measures kidney function by checking creatinine in your blood. Learn what eGFR means, how results are interpreted, and how to protect kidney health. Blood urea nitrogen-to-creatinine ratio. This test measures the amount of urea in your blood.Lowbloodcreatinine levels can mean lower muscle mass caused by a disease, such as muscular dystrophy, or by aging. Creatininelow in the blood is very rare. It may be due to a general disease or in case of unbalanced diets or malnutrition. It is recommended to do again the creatininebloodtest before thinking in any disease. Supplementing your diet with creatine can cause an increase in bloodcreatinine levels because creatinine is produced from creatine breakdown. Considering this when taking a creatininebloodtest is important because it is not necessarily a marker of kidney dysfunction in this case[8].