Creatinine test, what is it and how is it procedure?

Definition

What is creatinine?

Creatinine is a waste product of muscle metabolism which is used during muscle contraction. Creatinine is produced by creatine, which is an important molecule in muscles that functions to produce energy.

Before being excreted from the body through urine, creatine must first be filtered by the kidneys. The concentration level of serum creatinine should not change if the kidneys function properly.

If the kidneys have problems, creatinine levels can increase and accumulate in the blood. As a result, various diseases of the kidney and urinary system (urology) can also appear.

Therefore, tests are needed to test creatinine levels, both in blood and urine. That way, you can find out how well the kidneys function in filtering or what is commonly called the glomerular filtration rate (GFR).

Function

What is the function of the creatinine test?

Creatinine test serves to test the ability of the kidneys to filter blood and urine. If kidney function is disturbed, the rate of kidney cleansing will also be disturbed.

The creatinine test is usually also done in conjunction with other kidney function tests, including a blood urea level (BUN) test. Therefore, a creatinine test is often recommended when someone has a routine check-up.

Who needs a creatinine test?

You may need a creatinine level check if you or someone close to you has symptoms caused by kidney disease, such as:

• low back pain near the kidney area,
• swelling of the arms and ankles,
• high blood pressure,
• reduced frequency of urination,
• foamy pee, and
• blood in the urine (hematuria).

You may also need this examination if the results of blood or urine tests indicate that there is a problem with the kidneys.

In addition, there are several other conditions that can also affect kidney function that may require a creatinine test, namely:

• diabetes,
• hypertension,
• heart failure disease, and
• use drugs that affect the kidneys.

Preparation

What needs to be prepared for a creatinine test?

Examination of creatinine is divided into two methods, namely using blood and urine samples. Even so, the preparation for this kidney examination is not much different.

In general, before the creatinine test is done, you will be asked to fast overnight. If this is not possible, at least you should not eat cooked meat because it can affect creatinine levels.

In addition, the medical staff will also ask you to stop using the following medicines for a while.

• Aminoglycosides
• Cimetidine
• Chemotherapy drugs (cisplatin)
• Medicines that damage the kidneys, such as cephalosporin
• Non-steroidal anti-inflammatory drugs (NSAIDS)
• Trimethoprim

Procedure

What is the procedure for testing creatinine?

The creatinine test procedure is divided into two methods, namely blood tests and urine tests.

Urine test

Checking creatinine levels with urine may take longer than blood tests, which is 24 hours.

Your healthcare provider will usually provide you with a container to collect urine and instructions on how to collect and store samples. Here are some steps.

• Urinate immediately in the morning after waking up and record the time.
• For the next 24 hours, keep all urine excreted in a container.
• Store the urine container in the refrigerator or cooler with ice.
• Give the container containing the urine sample to the laboratory as instructed.

Blood test

When the creatinine level is tested with a blood sample, the health worker will draw blood from a vein in your arm. This is done with the help of a small needle.

After the needle is inserted, a small amount of blood will be collected into the tube. You may feel a little sore when the needle is inserted and removed.

This procedure usually only takes less than five minutes and is not much different from other blood sampling procedures.

Result

What are the results shown by the creatinine test?

Urine test

The creatinine level in urine collected for 24 hours normally ranges from 500 to 2000 mg / day. Each person's results may vary depending on age and amount of lean body mass.

Here's another way of expressing the normal range for a urine creatinine test.

• 14-26 mg / kg body mass per day for men (123.8 to 229.8 µmol / kg per day)
• 11-20 mg / kg body mass per day for women (97.2 to 176.8 µmol / kg per day)

Keep in mind that the normal number of creatinine in urine may vary from laboratory to laboratory. This is because some laboratories use different measurements or samples.

Therefore, always consult with your doctor about the meaning of your creatinine test results.

Blood test

In the blood creatinine test will usually be measured in the form of milligrams per deciliter or micromoles per liter. The following figures show that creatinine levels are categorized as normal.

• 0.6 - 1.2 mg / dL in adult male patients
• 0.5 - 1.1 mg / dL in female patients
• 0.5 - 1.0 mg / dL in adolescent patients
• 0.3 - 0.7 mg / dL in pediatric patients
• 0.2 - 0.4 mg / dL in patients under five
• 0.3 - 1.2 mg / dL in infant patients

Elderly patients may experience a decrease in creatinine levels because it is affected by reduced muscle mass. The numbers above can certainly vary because the amount of creatinine in the blood will increase with muscle mass.

Therefore, men usually have higher creatinine levels than women.

What does it mean when the creatinine test results are high?

If your creatinine levels are high, it means your kidneys are not functioning properly. There are several factors that trigger this condition in a short time, namely dehydration, using certain medications, or low blood volume.

If the test results show higher than normal creatinine levels, your doctor may order you to undergo a series of additional tests.

This aims to determine whether high creatinine is caused by various health conditions, such as:

• glomerulonephritis,
• kidney infection (pyelonephritis),
• bladder disease,
• inflammation of the kidneys, and
• rabdomyolysis.

Meanwhile, if your creatinine levels are low, it means you may experience depression or reduced muscle mass.

Most people may not need dialysis until the GFR or creatinine clearance test is reported to be very low. Even so, kidney function will continue to decline with age.

Therefore, it is important for everyone to maintain kidney health in order to keep working properly in filtering blood.

Side effects

Are there any side effects from the creatinine test?

There are no serious side effects caused by the creatinine test, either urine test or blood test.

However, you may feel some pain or bruising where the needle was injected. You don't need to worry because usually these symptoms will disappear quickly.

If you have further questions, please discuss with your doctor to find the right solution.