Serum Creatinine (Creatinine Level)

Why This Test Matters

Creatinine is a byproduct of muscle breakdown and is normally filtered out of your blood by your kidneys. If your kidneys aren’t working properly, creatinine builds up in your blood. High levels can indicate kidney damage or disease, while low levels might suggest dehydration or muscle loss.

What to Expect Before the Test

No special preparation is needed for this test. You may have a blood sample drawn from a vein in your arm, typically during a routine office visit or lab visit. If you’re dehydrated, your doctor might advise drinking extra fluids the day before.

What the Results Mean

Your results will be compared to a reference range, which can vary slightly by lab. High creatinine levels may signal reduced kidney function, while very low levels could be due to muscle weakness, malnutrition, or other conditions. Your doctor will interpret results in the context of your overall health.

Common Conditions Affecting Results

Kidney disease, dehydration, heart failure, or certain medications can affect creatinine levels. Other factors, like muscle mass or diet, may also influence results. If you have a history of these conditions, your doctor will consider them when reviewing your test.