Normal creatinine levels in the blood are 0.6–1.3 mg/dL.
Creatinine is a waste product that gets created in the body when muscle tissue and proteins are broken down. Creatinine is removed from the body by the kidneys. An increasing creatinine level is, therefore, a marker of kidney damage. Things that cause kidney damage and an elevated creatinine include dehydration, intrinsic kidney disease, certain medications (e.g., ibuprofen), and urinary obstruction.
In some cases, having a high creatinine is a result of working out, having high levels of muscle mass, or taking creatine supplements and is not a marker of kidney damage. Creatinine levels can be brought back into a healthy range by addressing the underlying problem (for example, rehydrating or stopping certain medications). In people with kidney disease, a very high creatinine level has a poor prognosis and may indicate that a person needs to go on dialysis.
What we mean by normal
In medicine, using the term “normal” can sometimes be off-putting. Saying something is “normal” implies that everything else is “abnormal.” Additionally, saying something is “normal” may not be accurate, since something that is “normal” for you may not be “normal” for somebody else. Therefore, instead of saying certain values are “normal,” alternative terminology may be to say that these values are “healthy” or “within the reference range.”
Additionally, some values have well-defined cutoffs, while others do not. For example, when looking at hemoglobin A1c levels, a value of 6.5 or greater is always diagnostic of diabetes. On the other hand, when looking at testosterone levels, some use cutoffs of 270–1,070 ng/dL while others use cutoffs of 300–1,000 ng/dL.
The information above represents values that are commonly used as cutoffs. However, depending on the specific source you’re looking at or the laboratory you go to, their values may be a little different.
If you have any medical questions or concerns, please talk to your healthcare provider. The articles on Health Guide are underpinned by peer-reviewed research and information drawn from medical societies and governmental agencies. However, they are not a substitute for professional medical advice, diagnosis, or treatment.
Dr. Tzvi Doron is Board Certified in Family Medicine by the American Board of Family Medicine and is Ro's Chief Clinical Officer.