Creatinine in the Blood: What is it? Normal Level, Blood Analysis, Indications, Preparation and Procedure

It is a waste product that comes from the normal wear and tear of the body’s muscles. Everyone has creatinine in their bloodstream.

What is the average level of creatinine?

In general, creatinine levels in adult men are 0.7 and 1.3 mg/dl, while in women, it is 0.5 and 1.2mg / dl, and in children, it is usually 0.2 and 1 mg/dl.

It also depends on your age, race, gender, and body size.

What is a creatinine blood test?

A creatinine blood test measures the level of creatinine in the blood.

The levels of this can indicate how well your kidneys are working and their condition, although it does not strictly determine if your kidneys are in poor condition.

If you have high levels of creatinine in your body, this could indicate that one of your kidneys is not working properly and is damaged.

Creatinine is one of the substances that the kidneys typically remove from the body. Doctors measure the creatinine level in the blood to monitor kidney function.


Creatinine blood tests are usually performed in conjunction with other laboratory tests, including a blood urea nitrogen (BUN) test and a basic metabolic panel (BMP) or panel. Metabolic rate (CMP).


Your doctor may order a creatinine blood test to evaluate your creatinine levels if you show signs of kidney disease. These symptoms include:

  • Fatigue and trouble sleeping.
  • A loss of appetite
  • Swelling in the face, wrists, ankles, or abdomen.
  • Low back pain near the kidneys.
  • Changes in urine output and frequency.
  • High blood pressure
  • Nausea.
  • Vomiting

Kidney problems can be related to different diseases or conditions, including:

  • Glomerulonephritis: This is an inflammation of the glomeruli due to damage.
  • Pyelonephritis: is a bacterial infection of the kidneys.
  • Prostate disease: like an enlarged prostate.
  • Urinary tract blockage: which may be due to kidney stones.
  • Decreased blood flow to the kidneys can be caused by congestive heart failure, diabetes, or dehydration.
  • Kidney cell death: as a result of drug abuse.
  • Streptococcal infections – such as post-streptococcal glomerulonephritis.

Aminoglycoside medications, such as gentamicin (Garamycin, Gentasol), can also cause kidney damage in some people.

If you are taking this type of medicine, your doctor may order regular blood tests to ensure your kidneys stay healthy.

How do I prepare for a blood test?

A creatinine blood test doesn’t require much preparation. Fasting is not necessary. You can and should eat and drink the same as usual to get an accurate result. However, you must tell your doctor about the prescription or over-the-counter (OTC) medications you are currently taking.

Some medications can increase creatinine levels without causing kidney damage and interfering with test results. Tell your doctor if you take:

  • Cimetidina (Tagamet, Tagamet HB).
  • Nonsteroidal anti-inflammatory drugs (NSAIDs), such as aspirin (Bayer) or ibuprofen (Advil, Midol).
  • Chemotherapy drugs.
  • Antibiotics of cephalosporin such as cephalexin (Keflex) and cefuroxime (Ceftin).

Your doctor may ask you to stop taking your medicine or adjust your dose before the test. They will also consider this when interpreting your test results.

What can I expect during a creatinine blood test?

The creatinine blood test is a simple test that requires the collection of a small sample of blood.

A phlebotomist, the technician who performs the blood draw, first asks you to roll up your sleeves to expose your arm.

They sterilize the injection site with an antiseptic and then tie a band around your arm. This causes the veins to fill with blood, making it easier to find a vein.

Once they find a vein (usually the inside vein in the elbow), they insert a needle into it to collect the blood. You may feel a slight prick when the needle is inserted, but the test itself is not painful. After the phlebotomist removes the hand, they place a bandage over the puncture wound.

A creatinine blood test is a low-risk procedure. However, there are some minor risks, including:

  • Fainting at the sight of blood.
  • Dizziness or vertigo.
  • Pain or redness at the puncture site.
  • Hematomas.
  • Pain.
  • Infection.

Once enough blood is drawn, the sample is sent to a laboratory for analysis. Your doctor will give you the results within a few days of testing.