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 normal level of creatinine?

In general, creatinine levels in adult men are 0.7 and 1.3mg / dl while in women it is 0.5 and 1.2mg / dl and in children it is usually 0.2 and 1mg / 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 give an indication of 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 be an indication that one of your kidneys is not working properly and is damaged.

Creatinine is one of the substances that the kidneys normally remove from the body. The level of creatinine in the blood is measured by doctors 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 : which is an inflammation of the glomeruli due to damage.
  • Pyelonephritis : which 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 – which 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 make sure 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 normal to get an accurate result. However, it is important that you tell your doctor about the prescription or over-the-counter (OTC) medications you are currently taking.

Some medications can increase your 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 to adjust your dose before the test. They will also take this into consideration 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 so your arm is exposed.

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 for them 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 small prick when the needle is inserted, but the test itself is not painful. After the phlebotomist removes the needle, 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.