What does creatinine test for?
Creatinine is a breakdown compound produced by working muscles. It is filtered out of the blood by the kidneys, then is released from the body in urine. In a healthy person, the level of creatinine is constant because the kidneys are able to filter it out as it is produced. This makes creatinine a useful biomarker to indicate how well the kidneys are functioning because a buildup of creatinine in your blood may indicate your kidneys are not filtering your blood properly.
What causes high creatinine levels?
Your creatinine levels can be elevated due to complications related to diabetes, medication toxicity, kidney infection, high blood pressure, heart disease, and conditions that block the flow of urine. Your healthcare professional may perform a urine test to confirm your blood levels.
Your level of creatinine depends on your age, ethnicity, gender, and muscle mass.
When should I measure my creatinine levels?
Your healthcare professional may recommend this test if you have symptoms of kidney disease, have a condition (e.g., diabetes or high blood pressure) that increases your risk of kidney disease, or to check on the effectiveness of treatment for kidney disease.
High levels of creatinine may not result in noticeable symptoms until kidney disease progresses. At that point you might experience swelling, fatigue, changes in urination, loss of appetite, nausea, and itching².
What is a normal creatinine level?
Blood levels of creatinine should be stable and the following ranges are considered normal¹:
- For adult men: 0.74–1.35 mg/dL
- For adult women: 0.59–1.04 mg/dL
Serum creatinine is used to measure the glomerular filtration rate (GFR), which takes into account age and sex when assessing kidney function¹.
What does a high creatinine level mean?
Elevated levels of creatinine may indicate poor kidney function and the possibility of kidney disease.
What does a low creatinine level mean?
Low levels of creatinine can be associated with low muscle mass due to aging, severe liver disease, or a low-protein diet.
How can I improve my creatinine levels?
Working with a healthcare professional to address the condition affecting your kidney function may help lower your creatinine levels back to normal. This could include dietary and lifestyle changes, including not smoking and limiting alcohol consumption.