Creatinine and kidney filtration
Biomarker library
Kidney Health
Creatinine
Creatinine is a waste product of normal muscle activity. Muscles release it at a steady rate and the kidneys filter it out, so its level in the blood is a good gauge of kidney filtering.
Measured in your health assessment, with a doctor to explain your result. Book yours
Why it matters
If kidney function falls, creatinine builds up. Because the amount depends on muscle mass, a bodybuilder and a slight older person can have very different normal levels, which is why creatinine is converted into eGFR.
What a result can mean
Lower than the range
A low creatinine usually reflects lower muscle mass, as in older age or after illness, and pregnancy, when the kidneys filter faster.
Higher than the range
A higher creatinine can mean reduced kidney function, but it also rises with more muscle, a large meat meal, creatine supplements, intense exercise, dehydration and some medicines.
What can help
Keeping blood pressure and blood sugar under control, staying hydrated and avoiding regular use of anti-inflammatory painkillers such as ibuprofen protect your kidneys. Skipping hard exercise and big meat meals the day before a test gives a truer reading.
Read it with
NoteGeneral educational illustration. Colours, sizes and movement are simplified. This is not a scan or a simulation of your body. General information, not personal medical advice: a doctor reads your own results with your history.
Know your creatinine.
Measured in your health assessment and explained by the doctor who reviews your results.