What is creatinine?

Creatinine on your report

Shown as serum creatinine in mg/dL, often with eGFR.

There is no one normal number, because it depends on:

• your muscle mass
• age
• diet
• activity

Labs print their own range. Your doctor will judge whether it is high for you.

What creatinine tells your doctor

If your kidneys are not filtering well, creatinine builds up in the blood.

That is why it is checked in people with:

• diabetes
• high blood pressure

These are the two most common causes of kidney damage.

Your lab uses creatinine, with your age and sex, to work out eGFR, an estimate of how fast your kidneys filter, which is more accurate than creatinine alone.

What moves your creatinine

Creatinine depends partly on how much muscle you have, so a muscular person may run a bit higher.

These can also raise it for a short while:

• a meat-heavy meal before the test
• intense exercise
• dehydration

Protect your kidneys long term by:

• keeping blood sugar and blood pressure in range
• using less salt and fewer packaged foods
• drinking enough water
• staying active

Don't change your protein intake or medicines without your doctor.