Creatinine is a chemical, a waste product made when we produce energy. Our kidneys normally remove creatinine from the blood and excrete it through urination. Therefore, blood test results that reveal high levels of creatinine mean that the kidneys are “failing” at their filtration.

Causes of Increased and Decreased Creatinine in the Body

The normal level of creatinine in the blood in adults is 0.8–1.2 mg/dL. However, the value range may vary in each laboratory.

Creatinine levels will usually be higher in young adults or people who have a lot of muscle tissue, for example athletes or people who often exercise weight lifting.

However, in addition to factors such as age, activity, and body muscle mass, increased creatinine levels can also be caused by certain medical conditions or diseases, such as:

  • Kidney problems, such as kidney failure, kidney stones, and kidney infections
  • Dehydration
  • Rhabdomyolysis
  • Hypertension
  • Diabetes
  • Side effects of certain drugs, such as antibiotics, chemotherapy drugs, and diuretics
  • Consume a lot of meat

Conversely, creatinine levels may decrease in people with malnutrition or liver disease. A decrease in creatinine levels is also often experienced by the elderly.