Know Your Blood Parameter: Serum Creatinine
- Summarised by TGHC Editorial Team
- Jun 23, 2025
- 3 min read
Updated: Dec 20, 2025
Parameter Name
Serum Creatinine
Serum creatinine is a crucial biochemical marker that reflects the level of creatinine in the blood, which is a waste product formed from the normal breakdown of muscle tissue. The kidneys filter out creatinine from the bloodstream, and its concentration in the serum is an important indicator of renal function.
Test Type
Blood
This test is performed on a blood sample, typically drawn from a vein in the arm. The blood sample is then analyzed in a laboratory to determine the concentration of serum creatinine. This test is often part of a comprehensive metabolic panel or renal function panel.
Normal Range
Men: 0.74 – 1.35 mg/dL
Women: 0.59 – 1.04 mg/dL
The normal range for serum creatinine levels can vary slightly depending on the laboratory and the measurement techniques used. It is important to consider factors such as age, sex, and muscle mass, as these can influence creatinine levels. Generally, higher levels may indicate reduced kidney function, while lower levels may be observed in individuals with decreased muscle mass.
High Levels Indicate
Impaired kidney function, dehydration, muscle injury, or medications.
Elevated serum creatinine levels can signify a variety of health issues. This may include chronic kidney disease (CKD), acute kidney injury (AKI), or conditions that affect kidney perfusion such as dehydration. Additionally, muscle injuries or diseases that cause muscle breakdown can lead to increased creatinine levels. Certain medications, particularly those that are nephrotoxic, can also result in elevated creatinine levels, indicating a need for careful monitoring.
Low Levels Indicate
Low muscle mass, malnutrition, pregnancy.
Low serum creatinine levels may occur in individuals with lower muscle mass, such as the elderly or those with muscle-wasting diseases. Additionally, malnutrition can lead to decreased creatinine production, as can physiological changes during pregnancy, where increased blood volume can dilute serum creatinine levels.
Why It's Tested
Core marker to assess kidney filtration ability.
The serum creatinine test is a fundamental diagnostic tool used to evaluate kidney health. It helps clinicians determine how well the kidneys are filtering waste products from the blood. This information is vital for diagnosing kidney disorders, monitoring existing conditions, and guiding treatment decisions.
Associated Symptoms (if abnormal)
Swelling, fatigue, confusion, decreased urine output (in advanced stages).
Abnormal serum creatinine levels can be associated with a range of symptoms. Patients may experience swelling, particularly in the legs and ankles, due to fluid retention. Fatigue and weakness are common as kidney function declines and waste products accumulate in the body. In more severe cases, confusion and altered mental status may arise, especially if kidney function is significantly impaired. A notable decrease in urine output can also occur in advanced stages of kidney disease.
What To Do If Abnormal
Repeat test, calculate eGFR, consider imaging and full kidney panel.
If serum creatinine levels are found to be abnormal, it is crucial to repeat the test to confirm the results. Alongside this, calculating the estimated glomerular filtration rate (eGFR) can provide further insights into kidney function. Depending on the clinical scenario, healthcare providers may recommend imaging studies, such as ultrasound or CT scans, and a comprehensive kidney panel to assess other renal parameters and identify underlying causes.
Common Conditions Related
CKD, AKI, muscle disorders
Serum creatinine levels are closely associated with several medical conditions. Chronic kidney disease (CKD) is characterized by a gradual decline in kidney function over time, while acute kidney injury (AKI) reflects a sudden loss of kidney function. Additionally, various muscle disorders, including rhabdomyolysis, can lead to increased levels of serum creatinine due to muscle breakdown and the subsequent release of creatinine into the bloodstream.
Nutrition or Lifestyle Connection
Stay hydrated, manage blood pressure and diabetes, reduce salt/protein as needed.
Maintaining a healthy lifestyle can significantly influence serum creatinine levels and overall kidney health. Staying adequately hydrated helps support kidney function and facilitates the elimination of waste products. Managing blood pressure and blood sugar levels is essential, particularly for individuals with diabetes or hypertension, as these conditions can exacerbate kidney damage. Additionally, dietary modifications, such as reducing salt intake and moderating protein consumption, may be beneficial for those at risk of kidney disease or those already diagnosed with renal issues.
References (APA Format)
NIH. (2023). Creatinine test.
MedlinePlus. (2023). Serum creatinine.
Mayo Clinic. (2022). Kidney tests overview.
