Creatinine Serum
Also known as
Creat, Blood Creatinine, Serum Creatinine, Urine Creatinine, Creatinine
This test is ordered by the doctor to monitor the health of the kidneys in order to help diagnose kidney disease and monitor ongoing treatment for kidney disease.
This test is often part of a comprehensive metabolic panel or a basic metabolic panel which are ordered as part of routine check-ups. The test is also ordered when the patient has signs or symptoms related to kidney disease or damage. Or if the patient has a condition that may impact kidneys or be further derailed by kidney dysfunction. It is also ordered at intervals when the patient is being treated for kidney disease or function when on certain medications.
This is either a blood test or a urine test. For the blood test, a blood sample is drawn from a vein in the arm using a syringe. For the urine test, a 24-hour sample is required, while in some cases, a single, random sample of urine is needed. The urine must be collected in a clean container.
This is a blood and urine test. For the urine test, it is essential that you collect all the urine over the 24 hour period, wasting none of it in order to make sure the results are accurate. On the other hand, for the blood test, it is essential that the patient fast overnight or refrain from eating cooked meat as studies have shown that eating meat temporarily increases the levels of creatinine found in the blood.
Creatinine is a waste substance found in the body. It is made by the muscles as a by-product of the breakdown of creatine, which is a compound. Creatinine is removed from the body by the kidneys. Most of it is filtered from the blood and released into the urine to be eliminated from the body. This test is used by the doctor to measure how much creatinine is present in the blood or the urine. The compound creatine is key to the cycle, which makes the energy needed to contract muscles. Creatine and creatinine are produced by the body and present in it in stable amounts. Normally, most of the creatinine is filtered from the blood by the kidneys and removed from the body via excretion, which is why blood composition is a good indicator of how well the kidneys are functioning.
The amount of creatinine produced in the body is dependent on the body size and muscle mass which is why levels of creatinine a little higher in children and women. The kidneys are a pair of bean-shaped organs that are found at the bottom of the ribcage. Structurally, the kidneys contain millions of tiny blood-filtering units called nephrons. Within the nephrons, the blood is filtered through the glomerulus. The glomerulus allows water and small molecules to pass but prevents the
blood cells
and larger molecules from passing out. The tubules attached to the glomerulus collect fluid and molecules which pass through the glomerulus, which reabsorbs what can still be utilised by the body, while the remaining matter is excreted in the urine. The results from this test are used in combination with others, like the 24-hour creatinine test, in order to calculate values that are helpful in assessing how the kidneys are functioning.
This test used to evaluate if the kidneys are working effectively or not. Commonly, it is ordered alongside blood urea nitrogen, another kidney test or as part of the comprehensive metabolic panel. The
CMP
provides a holistic assessment of various functions in the body. It is ordered routinely as part of general health check-ups. In addition, the creatinine is ordered to monitor how the kidneys are functioning and how the treatment is progressing when evaluating someone with diseases that can impact kidney function. Results from the test can also be used to estimate how much blood is filtered per minute by the kidneys; this is known as the estimated glomerular filtration rate, which is useful to screen for and detect early kidney damage, diagnose chronic kidney disease and monitor kidney status.
The test is ordered if the patient has symptoms of kidney diseases, such as
Fatigue
Puffiness around the eyes
Swelling in your feet and/or ankles
Decreased appetite
Frequent and painful urination
Urine that is foamy or bloody
The test is also ordered if the patient is at risk for kidney disease. Examples of conditions that create such a risk include:
Type 1 or type 2 diabetes
High blood pressure
A family history of kidney disease
Higher levels of creatinine in the blood and lower levels of creatinine in the urine imply kidney disease or other conditions which may impact kidney function. For example,
Autoimmune diseases
Bacterial infection of the kidneys
Blocked urinary tract
Heart failure
Complications of diabetes
However, an abnormal result does not always indicate the prevalence of kidney disease. Creatinine levels may be raised because of:
Pregnancy
Intense exercise
A diet high in red meat
Certain medicines. Some medicines have side effects that raise creatinine levels.
Related Tests
Blood Urea Nitrogen (BUN), Estimated Glomerular Filtration Rate (eGFR), Creatinine Clearance, Comprehensive Metabolic Panel , (CMP), Basic Metabolic Panel , (BMP), Urinalysis, Urine Protein and Urine Protein to Creatinine Ratio, Urine Albumin and Albumin to Creatinine Ratio, Renal Panel, Cystatin C, Beta-2 Microglobulin Kidney Disease
