Kidney Function Test (KFT)
A group of tests used to evaluate how well the kidneys are working.
Kidney Function Test (KFT)
A group of tests used to evaluate how well the kidneys are working.
Also known as
- Renal function test
- RFT
- Creatinine
What it measures
- BUN (blood urea nitrogen)
- Creatinine (blood, and sometimes urine)
- Creatinine clearance, and an estimated filtration rate calculated from creatinine
Why a doctor may order it
May be part of a routine checkup, used to monitor a kidney condition and its treatment, or advised if you are at risk of a kidney problem — early kidney disease often has no signs or symptoms.
What it helps evaluate
It can help a doctor check the health of the kidneys and look for kidney disease. Creatinine alone isn't the best measure, because it varies with muscle mass, diet, age and activity.
Preparation
Your provider will tell you how to prepare. For creatinine you may be asked not to eat meat for 24 hours beforehand, because meat can temporarily raise creatinine.
Fasting
A BUN test usually needs no special preparation. If the tests are part of a wider panel you may need to fast — up to 12 hours for some panels. Your provider or lab will tell you.
Important considerations
- Certain medicines and supplements can affect results — tell your provider what you take.
Discuss results with your doctor
Talk to a doctor about your symptoms and about what your results mean — a single result is not a diagnosis. See a doctor promptly for severe or worsening symptoms.