Creatinine

The Creatinine test measures the level of creatinine in the blood. Creatinine is a waste product produced by muscle metabolism and excreted by the kidneys. It is a reliable indicator of kidney function. Elevated or reduced creatinine levels can help assess how well the kidneys are filtering waste from the blood.

1. What Is Creatinine?

• Creatinine is produced from the breakdown of creatine, a molecule important for energy in muscles.

• It is filtered from the blood by the kidneys and excreted in the urine.

• Creatinine levels remain relatively stable in individuals with normal kidney function.

2. Why Is the Creatinine Test Performed?

This test is used to:

• Assess kidney function.

• Help diagnose and monitor chronic kidney disease (CKD).

• Monitor the effects of medications that may impair kidney function.

• Evaluate dehydration, muscle disorders, or severe infections.

3. Creatinine Reference Range

• Normal range (adults):

  - Men: 0.7 – 1.3 mg/dL

  - Women: 0.6 – 1.1 mg/dL

• Reference values may vary slightly depending on lab, age, sex, and muscle mass.

4. How to Interpret Creatinine Results

🔹 Elevated Creatinine:

• Suggests impaired kidney function or kidney disease.

• May also occur with dehydration, urinary tract obstruction, or certain medications.

🔹 Low Creatinine:

• May be seen in reduced muscle mass, advanced liver disease, or pregnancy.

• Usually not a concern unless accompanied by other abnormal lab values.

5. What Can Affect Creatinine Levels?

• Kidney disease or injury

• Dehydration or fluid loss

• Muscle mass and physical activity

• Certain medications (e.g., NSAIDs, ACE inhibitors, chemotherapy)

• High protein diet or creatine supplements

6. How Is the Test Performed?

• A blood sample is taken from a vein.

• Sometimes, a 24-hour urine collection is also ordered to measure creatinine clearance.

7. When to See a Doctor

🚨 Contact your healthcare provider if you:

• Have abnormal creatinine levels on routine testing.

• Experience signs of kidney problems such as fatigue, swelling, or changes in urination.

• Take medications that may affect kidney function.

🔹 Key Takeaways

✅ Creatinine is a key indicator of kidney function and health.

✅ Elevated levels may suggest kidney impairment or dehydration.

✅ Regular monitoring is important for individuals with kidney disease, diabetes, or hypertension.