What Causes High Creatinine Levels?

Medically Reviewed on 2/21/2023
Creatinine blood test
The normal range of creatinine levels may differ from age, sex, size, and muscle buildup of the person.

The body produces various harmful chemicals as byproducts of metabolism. Creatinine, one such chemical, is released by muscle cells when they degenerate naturally as a result of wear and tear or aging.

  • The kidneys eliminate creatinine from the body through urine.
  • It can be detected both in blood and urine.
  • A blood test can help determine the presence of excess creatinine caused by any abnormality in the body.

The normal range of creatinine levels may differ from age, sex, size, and muscle buildup of the person.

If the creatinine level rises beyond the normal range in the blood, it indicates:

Some diseases that affect the kidneys reduce the functionality of the kidneys and result in high creatinine in the blood.

How to diagnose high creatinine levels in the body

Creatine can be measured in both blood and urine in the following ways:


A blood sample is collected from a vein and sent to the lab for analysis.

The normal range of creatinine levels in the blood are:

  • Males: 60 to 110 mcmol/L or 0.7 to 1.2 mg/dL.
  • Females: 45 to 90 mcmol/L or 0.5 to 1.0 mg/dL.


A urine sample is collected early in the morning and sent for analysis.

The normal range of creatinine levels in urine are:

  • Males: 995 to 2936 mg/24 hours.
  • Females: 601 to 1689 mg/24 hours.

What are the symptoms of high creatinine levels in the blood?

A spontaneous and temporary elevation of creatinine may be caused by certain medications, intake of high amounts of proteins or red meat, or dehydration. However, persistently high creatinine levels are a serious issue that indicates kidney damage.

The symptoms of high creatinine in the body include:


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What is creatinine clearance?

This test determines how well the kidneys perform and how well the blood flows to them. 

  • Creatinine is a waste product produced by regular muscle activity as well as animal protein in the diet.
  • It is removed from the blood by healthy kidneys and is then excreted from the body via urine.

Typically, the creatinine clearance test compares the creatinine level in a 24-hour urine sample to the creatinine level in the blood. This shows how well the kidneys are operating and helps the doctor determine the glomerular filtration rate (the quantity of blood cleansed per minute by glomeruli, which are microscopic filters in the kidneys).

How is a 24-hour urine creatinine test performed?

One sample for a spot urine test, ideally early in the morning, is collected.

To get a 24-hour urine sample, one must collect all the urine excreted for 24 hours.

  1. First thing in the morning, empty the bladder thoroughly without collecting the sample. Take note of the time.
  2. Then, over the following 24 hours, one should collect samples every time one goes to the restroom.
  3. After each collection, store the urine in the refrigerator or in a cold area. 
  4. Once finished collecting the urine for 24 hours, it may be sent to the lab for testing

What factors affect the result of the urine creatinine test?

The urine creatinine level may be greater than usual if a person is muscular, and the levels are lower than normal if a person is of petite stature or have little muscle mass due to illness.

  • Urine creatinine levels may vary with ethnicity. People belonging to a particular ethnicity may have slightly higher levels, which is considered normal.
  • Certain medications may have an impact on the findings.

How to treat high creatinine levels in the body

High creatinine levels can be caused by a variety of factors, and the symptoms may differ depending on the etiology.

  • In many circumstances, drugs can help alleviate excessive creatinine levels by addressing the underlying disease.
  • Drugs to treat high blood pressure may help the endothelial damage seen in the renal blood vessels in diabetes and hypertension.
  • Plenty of hydration and dietary restrictions on sodium, protein, and uric acid-containing foods are a must.

Dialysis, in addition to drugs, to help filter toxins and waste products from the blood could be necessary in cases of renal failure. A kidney transplant may be required in severe or end-stage cases.

Medically Reviewed on 2/21/2023
University of Rochester Medical Center. Creatinine Clearance. https://www.urmc.rochester.edu/encyclopedia/content.aspx?contenttypeid=167&contentid=creatinine_clearance_blood

Hartford HealthCare. Creatinine and Creatinine Clearance. https://hartfordhospital.org/health-wellness/health-resources/health-library/detail?id=hw4322