What is Creatinine?
Creatinine is a metabolite, a by-product of creatine, which is itself a nitrogen-containing compound that serves as a source of energy in muscle cells. It is created from creatine, which is synthesized from the amino acids lysine, methionine, and glycine. The main function of creatinine is to be filtered out of the blood by the kidneys and excreted through urine. Thus, creatinine levels in the blood can be used to assess kidney function because altered levels may indicate kidney disease or impairment.
Creatinine test is conducted to measure the levels of creatinine in the blood. Low kidney function leads to an increased blood creatinine level because the kidneys are not able to filter out the waste properly.
How is the Test Performed?
The creatinine test is a simple blood test that is minimally invasive;
Preparation
- Fasting is required if instructed by the healthcare provider.
- No special preparation is needed for the test
Laboratory Analysis
- The sample is analyzed using advanced techniques such as Jaffe method, enzymatic method, or immunoassays for accurate results.
What are the symptoms that prompt this test?
The healthcare providers suggest this test if an individual is showing the following symptoms of renal insufficiency, such as;
General Symptoms
- Swelling of the hands, ankles and feet, condition called edema
- Urinating frequently
- Bubbly or foamy urine
- Presence of blood in the urine
- Vomiting
- Nausea
- Change in urine output
- Loss of appetite
What are Normal Ranges for This Test?
The generally accepted reference range for creatinine is mentioned below. It is important to note that the creatinine levels vary according to the age, sex, mass of the muscles, and overall general health of an individual.
Neonates – 2 to 0.6 mg/dL
Children – 3 to 0.7 mg/dL
Men – 6 to 1.2 mg/dL
Women – 5 to 1.1 mg/dL
**The values above are general guidelines only and may vary according to the test assay. Always consult your healthcare provider for the correct interpretation of the results according to your health condition. **
What Happens if Test Results Show Abnormal Levels?
Elevated levels of creatinine indicate that the person is affected with kidney disorder and the renal function is not optimal. The following conditions can be present;
- Chronic kidney disease
- Acute kidney injury
- Dehydration
- Kidney stone
- Kidney infection
If abnormalities are diagnosed further testing is recommended by the doctor involving glomerular filtration rate (GFR) test, urine albumin test, and an ultrasound of the kidneys for the confirmation of the disease along with medications and lifestyle modifications.
