Creatinine, Serum

What is Creatinine (Serum) Test?

• A blood test that measures the level of creatinine, a waste product produced by muscle metabolism.
• It reflects how well the kidneys are filtering blood.

Key Parameter

Why It Is Done

• Routine health check‑ups.
• Evaluation of symptoms like swelling, fatigue, or changes in urine.
• Monitoring kidney function in people with diabetes, hypertension, or chronic kidney disease.

Early Detection

The test can help identify signs of kidney dysfunction or renal impairment, but it does not diagnose a disease on its own. A doctor interprets the result with symptoms, history, and other tests.

What Abnormal Results Mean

• High creatinine may indicate reduced kidney filtration, dehydration, certain medications, or muscle injury.
• Low creatinine can occur with low muscle mass, malnutrition, or pregnancy.

Factors such as hydration, diet, exercise, and medications can affect the result.

Who Should Get It

• Adults with risk factors for kidney disease (diabetes, hypertension, family history).
• Patients on nephrotoxic drugs.
• Individuals with unexplained swelling or changes in urine.

Quick Summary

Creatinine testing checks kidney filtering ability. It’s a routine part of kidney health monitoring and helps flag potential problems early.

Preparation

• Fasting: Not required.
• If you are also doing a fasting blood sugar or lipid panel, fast for 8–12 hours.
• Procedure: A healthcare professional will draw 5–10 mL of blood from a vein in your arm using a sterile needle. The process takes about 5 minutes.
• Comfort: You may feel a brief pinch when the needle is inserted.
• Precautions: Stay well‑hydrated, avoid alcohol and strenuous exercise 24 hours before the test. If you are on medication that affects kidney function, inform the clinician.
• Next steps: Confirm any specific instructions with your doctor or the lab. This information is educational and not a substitute for professional medical advice.