Creatinine Test

What is the creatinine test ?

A creatinine test is a blood examination to evaluate creatinine levels in the blood.  The level of creatinine in the blood is a significant indicator of the health of your kidneys.  The creatinine test is also known by another name such as serum creatinine.

Our muscles have a compound called creatine which is used to provide energy to the muscles.  When creatine breaks down in the muscle to release energy, creatinine is released as a waste product. This is carried in the bloodstream to the kidneys which help eliminate creatinine from the body.

The creatinine blood test helps evaluate how your kidneys are working. This means if your creatinine levels are high, your kidney function is not up the mark. Deficient kidney function will result in improper filtration of creatinine causing its levels to be high in the blood. Result of the creatinine blood tests is used to calculate the glomerular filtration rate (GFR), which points to how the kidney is performing overall. This test helps healthcare providers diagnose chronic kidney disease.

Why should I undergo a creatinine blood test?

Your doctor may have asked for a creatinine blood test to evaluate your creatinine levels especially if you have been suffering from the following symptoms that could point towards potential kidney disease. The tests help rule out kidney disease or make a confirmed diagnosis.

Some of the major signs and symptoms of chronic kidney disease may escape attention. This makes creatinine tests all the more necessary and important.

– Hypertension
– Pain in the lower back
– Reduced appetite
– Nausea and vomiting
– Tiredness
– Sleeplessness
– Swelling in the ankles, abdomen, wrist or face
– Alterations in the urine output

The presence of any of the following health conditions or practices can also cause problems in the way kidneys process creatinine.

– Swelling of glomeruli medically called glomerulonephritis.
– Pyelonephritis, which is a bacterial infection of the kidneys.
– Prostate enlargement.
– Any obstruction in the urinary tract.
– Reduced blood flow to kidneys due to other medical conditions.
– Kidney damage triggered by substance abuse.
– Prolonged use of certain medications.
– Blocked urinary tract.
– High-protein diet.

What goes into the preparation for this test?

The preparation for a creatinine blood test is fairly simple. Inform your specialist about your health conditions. Specifically, communicate about all the medicines you are taking, even the over-the-counter (OTC) medications.

– This is imperative since some of the medications may elevate your creatinine levels without any adverse impact on the kidneys.

– Also, it is good to inform your doctor if kidney disease exists in the family.

– You should also inform your specialist about your level of physical activity every day.

Typically watch out for some of the below-mentioned drugs. If you are taking any of these medicines, keep your doctor posted.

-Nonsteroidal anti-inflammatory drugs (NSAIDs)
– Chemotherapy drugs
– Cimetidine (Tagamet, Tagamet HB)
– Cephalosporin antibiotics
At best, your specialist may ask you to stop the medicines until the test is over or even adjust the dose. Some antibiotics like Trimethoprim, and H2 blockers- for instance, cimetidine, can result in elevated serum creatinine levels, albeit temporarily.

Do I need to fast before a creatinine test?

You need not be on an empty stomach before the creatinine test. In fact, for an accurate blood report, you need to eat and drink fluids as you would normally do.

How is the creatinine blood test performed?

A creatinine blood test is easy and quick. It follows the below-mentioned procedure:

-The healthcare provider sterilizes your exposed arm with an antiseptic. They tie a band around your arm so that the veins are prominent. 

– They insert a needle into the vein to draw a sample of blood. It is as painful as a pinprick and after the procedure, a cotton swab is given to dab on the puncture wound.

– The blood sample is now sent for testing to the laboratory.

When will I get the results of the creatinine blood test?

The results of the creatinine blood test will be available a few days after the test.

What are the normal values for creatinine test?

The unit of measure for creatinine is milligrams per deciliter of blood (mg/dL).

How to interpret creatinine test results?

For both men and women, above 60 years, the reference range of serum creatinine level is almost the same as the 18-60 age groups. Elevated levels of serum creatinine levels in the blood point to malfunction of the kidneys. Using the serum creatinine blood test result, doctors calculate GFR, which is a significant marker for chronic kidney disease.

GFR reference range

– Below 60 – kidney disease
– 60 and above – normal
– 15 or below – kidney failure

My serum creatinine level is high. What does it mean?

If your serum Creatinine levels are high in the blood, it means that your kidneys are not functioning as well as they should be. The level will not improve until the underlying problem in your kidneys is resolved.

In case the levels of serum creatinine are high due to dehydration, or intake of supplements, or a very high protein diet, it will improve once you remedy these temporary conditions.

It is very rare to have low levels of creatinine. This can only occur if you are experiencing certain medical conditions that cause reduced muscle mass. This is not as worrying as elevated serum creatinine levels.

What are the causes of a low level of serum creatinine in the blood?

Some people have lower than normal levels of Creatinine in their blood. This could be due to the following reasons:

– Low muscle mass causes reduced levels of creatinine. For instance – senior adults.

– During pregnancy, there is an increase in urine output. This can cause low creatinine levels.

– The presence of medical conditions such as muscular dystrophy and myasthenia gravis.

-Extreme weight loss.

What is the cost of creatinine test in India?

The cost of creatinine test in India varies across cities and facilities It can cost anywhere between Rs. 90 to Rs. 200.

Is evaluating serum creatinine levels the best way to ascertain kidney health?

No. This is because there are factors such as body size, race, age and gender which also influence the level of creatinine in your blood. The best method to know about your kidney health is by evaluating your GFR which is the glomerular filtration rate (GFR).

What is GFR?

This is a routine lab test. GFR is arrived after taking into account your weight, age, gender, race, and serum creatinine levels. The GFR number will help your specialist ascertain whether you have kidney disease.

What are factors play an important role in keeping creatinine levels regulated?

Physical activity and the dietary choice you make is key to keeping your creatinine levels in check

What is the connection between exercise and creatinine levels?

A study conducted in 2012 observed that there was a spike in serum creatinine levels in the blood after intense exercise. Therefore, overexertion did cause an increase in creatinine in the blood although, temporarily. Patients with high creatinine levels must avoid heavy exercise at least till the levels return to normal and the treatment is completed.

How does the kidney eliminate waste products?

Your kidneys consist of tiny filtering units known as nephrons. These nephrons are millions in number and they function to continually filter the blood of impurities. The filtration process is archived through tiny blood vessels called glomeruli. These blood vessels filter impurities, waste products and excess water from the blood. These impurities reach the bladder and are thrown out of the body during urination.

What are the other blood tests usually performed with a creatinine test?

Many other laboratory tests are performed along with Creatinine blood tests to evaluate kidney function. These tests include

Blood urea nitrogen (BUN): This test evaluates the amount of urea nitrogen in the blood.

Basic metabolic panel (BMP) or comprehensive metabolic panel (CMP) test measures the functioning of kidneys by assessing acid-base, electrolyte balance, and blood glucose level.

What is the effect of pregnancy on the kidneys?

During pregnancy, the kidneys are larger. This is because of fluid retention.  There is an alteration in the way electrolytes and water is handled by the kidneys during pregnancy. The Glomerular filtration rate (GFR) goes up by 50% and renal plasma flow (RPF) is up 80% in comparison to those who are not pregnant. This increase in GFR during pregnancy causes a reduced concentration of serum creatinine.

What are some of the Dos and Don’ts to keep creatinine levels in check?