What is Creatinine Level in Blood Test?

What is Creatinine Level in Blood Test What is Creatinine Level in Blood Test

What is Creatinine Level in Blood Test – Overview

A creatinine blood test is devised to measure the level of creatinine in your blood. This substance is a waste product that is formed when creatine, found in your muscles, begins to break down.

Creatinine levels in the blood can let doctors know the functionality of your kidneys.

What Is a Creatinine Blood Test?

Our kidneys have millions of small filtering units called nephrons. The nephrons continuously filter blood and remove impurities and toxins from it by passing the blood through glomeruli.

These are clusters of tiny blood vessels that filter excess water, waste products, and other irregularities from the blood.

The nephrons segregate toxins from the blood into the bladder, which are then expelled from the body through urination.

Creatinine is one of the substances that your kidneys normally extract and expel from your bloodstream.

Doctors can measure the level of creatinine in your body to determine kidney functions. High levels of creatinine can be a sign of damage to the kidney or a kidney malfunction.

A creatinine blood test is usually performed in combination with several other tests, including basic metabolic panel (BMP) and blood urea nitrogen (BUN) tests.

These tests are normally performed during a routine physical exam and help diagnose certain diseases. These tests are also helpful to detect several types of problems with kidney functions.

Why is Creatinine Blood Test recommended?

What is Creatinine Level in Blood Test

What is Creatinine Level in Blood Test – Why is Creatinine Blood Test recommended?

Doctors may order you to undergo a creatinine blood test to measure the level of creatinine in the body and search for signs of kidney malfunctions. The symptoms most commonly identified using these tests include:

  • Loss of appetite
  • Trouble sleeping
  • Fatigue
  • High blood pressure
  • Nausea
  • Lower back pain near the kidneys
  • Swelling in the face, ankles, wrists or abdomen
  • Changes in urine frequency and output
  • Vomiting

Different diseases and disorders can also affect kidney functions, such as:

  • Pyelonephritis – Bacterial infection of kidneys
  • Glomerulonephritis – Inflammation of glomeruli due to damage
  • Blockage of the urinary tract – caused by kidney stones
  • Dead kidney cells from drug abuse
  • Decreased blood flow to the kidney from diabetes, congestive heart failure or dehydration

Certain medications, such as gentamicin can also cause damage to the kidney in some people. So, if you are taking this medication then your doctor may recommend undergoing a creatinine blood test from time to time to determine its level in your bloodstream.

How can I prepare for the Creatinine Blood Test?

A creatinine blood test does not require much preparation. You do not need to fast for this test. You should eat and normally drink as you do to get an accurate result.

However, you should also remember to inform your doctor about any over-the-counter medications or prescription drugs you are currently taking.

Some medicines and drugs have a tendency to increase creatinine levels without affecting kidney functions and may prohibit accurate test results.

How is Creatinine Blood Test Performed?

The creatinine blood test is a simple blood test that requires the lab technician to remove a small sample of your blood.

The lab technician will normally procure the blood sample from your arm, possibly from a vein near the elbow. Once the technician has removed a sufficient quantity of blood sample, they will cover the needle puncture with a bandage.

Although creatinine blood tests do not have any major risks, there are small complications that may be experienced by some. These include:

  • Dizziness or vertigo
  • Pain
  • Bruising
  • Infection
  • Soreness/redness at the puncture site
  • Fainting at the sight of blood

Once your blood sample is drawn, it is sent to a laboratory for analysis. You can expect to get the test results in a few days.

What do Creatinine Levels in the blood mean?

Creatinine levels in the blood are measured in milligrams per deciliter (mg/dL). People with larger muscles tend to have naturally high creatinine levels in their blood. The test results may also be influenced by your age and gender.

Generally, normal creatinine levels range from 0.9 to 1.3 mg/dL in men and 0.6 to 1.1 mg/dL in women between 18 and 60 years of age. For people over 60 years old, normal creatinine levels remain roughly the same.

If high serum creatinine levels are found in the blood, then it usually indicates the kidney not functioning normally.

There are other causes for high serum creatinine levels in the body too, such as kidney problems, a high-protein diet, reduced blood flow to the kidney, etc.


If the creatinine level in your blood is abnormally elevated and caused by a chronic or acute renal injury, the level of creatinine will not lower until the root cause is remedied.

If the elevated creatinine level in the bloodstream is caused by other conditions, then these conditions need to be treated to lower the creatinine levels to normalcy.

See Also

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I am a dedicated healthcare researcher and an enthusiast specializing in medical grants, medical education and research. Through my articles, I aim to empower healthcare professionals and researchers with valuable insights and resources to navigate these critical aspects effectively.

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