Introduction
Kidney function tests are very literal- in that your blood or urine samples are used to ascertain parameters related to kidney functioning, and if the values are skewed, then we know that something may be off. Kidneys perform a multitude of functions- like purifying all the blood in the body, helping maintain blood pressure by production of renin, vitamin D production etc. The primary role of the kidneys is to excrete toxic or unnecessary metabolites from the body, and if they don’t work well, it means these metabolites may build up in the body to toxic levels. An example for a kidney function test (KFT) is to check for creatinine or uric acid levels, among other parameters.
What is done as part of a Kidney Function Test (KFT)?
Some of the common parameters that are checked include the value or concentration of certain metabolites, while others aim to check how the glomeruli (the filtration unit of the kidney) are working. They are-
- Blood uric acid levels
- Blood urea nitrogen (BUN)
- Creatinine
- Electrolytes – sodium, chloride, potassium
- Estimated Glomerular Filtration Rate (eGFR)
- Proteinuria- protein in urine like albumin
- Urinalysis- analysis of urine for proteins and blood related markers
Something called a 24-hour urine test may also be done where you will be asked to give all your urine samples in marked containers- for 1 full day- to specifically check if creatinine and urea are cleared from the blood within the timeframe. Some may need some preparation like fasting, before giving a blood or urine sample. Your physician will give you the best advice on this. The results will help understand your condition, and help them come up with a treatment plan.
When Do You Need a Kidney Function Test (KFT)?
It is not just one type, but a whole battery of tests that may be conducted to get a full picture of what is going on with your kidneys. Not everyone needs them, and you should only get them if you display certain abnormal symptoms like –
- Having to pee too often
- Painful sensation while peeing
- Hematuria or blood in the urine
- Swelling of the limbs due to fluid retention
Conclusion
KFTs when properly done, and interpreted in the right manner can help immensely- as the kidneys perform one of the most important bodily functions, namely filtration of blood, Kidney function is also dependent highly on other disorders like diabetes, hypertension, or other lifestyle related conditions. If chronic kidney disease (CKD) is not diagnosed at the right time, then there may even be the need for a kidney transplant (if the degree of damage is too severe to be dealt with). Someone with CKD will also need regular KFTs to ensure that their disease has not progressed too far, and to see how it can be managed. So, this can in fact be a life saving diagnostic test in the grand scheme of things.
FAQs
Q1. Why are Kidney Function Tests (KFT) important?
Any abnormal values in your KFT can serve to alert you to a possible issue, even before symptoms may show. Also, they will help formulate a feasible treatment plan for the long term, as CKD has no cure. All medications or lifestyle changes focus on slowing the progression of the disease, and concentrate on improving the quality of life of an individual.
Q2. Who should undergo Kidney Function Tests (KFT)?
Anyone who is diabetic or who has hypertension, who is above 60 years of age, is obese, or has a history of heart disease should get a KFT done at least once a year. Same goes for if you have had multiple UTIs or obstructions over the last few months.
Q3. How often should Kidney Function Tests (KFT) be done?
The frequency is decided based on the severity of the symptoms, but usually it is about once a year.
Q4. What happens if Kidney Function Tests (KFT) indicate abnormalities?
Abnormally high or low values indicate that there may be a problem with the way your kidneys are functioning. Detailed tests are then used to narrow down the exact cause, and these are usually done by an experienced nephrologist.
Q5. Can lifestyle changes impact Kidney Function Test (KFT) results?
Absolutely! Consuming less sodium, drinking a lot of water, not drinking or smoking, having a balanced diet with some regular exercise- all of these can help reduce the quicker onset of symptoms, and even stem the progression of CKD for a while.
Q6. Can Kidney Function Tests (KFT) detect kidney stones or urinary tract infections (UTIs)?
The presence of blood or certain related infection markers in the urine may indicate kidney stones or UTIs. But, imaging is a better diagnostic tool to use in this case, and may be done right after a KFT, for a definitive finding.
