Glomerular Filtration Rate (GFR) Test: Meaning, Results & Levels

The kidneys play a vital role in facilitating the filtration process within the human body. Their primary function is to eliminate waste materials through urine production. The glomeruli, microscopic filters located within the kidneys, are responsible for this crucial filtration process. When the kidneys do not function properly, the effectiveness of the glomeruli is affected.

If your physician suspects any abnormalities related to kidney function, they may recommend a Glomerular Filtration Rate (GFR) test procedure.

What is a Glomerular Filtration Rate (GFR) Test?

The filtration capacity of the kidneys can be significantly impaired when affected by a disease. This leads to difficulties in effectively filtering waste and blood. The GFR test plays a crucial role in evaluating the volume of blood that the kidneys can filter within a minute, thereby aiding in the identification and assessment of kidney disease. Some doctors recommend an estimated GFR test, known as eGFR, which relies on the analysis of waste substances present in the blood to gauge kidney function.

To determine the estimated glomerular filtration rate (eGFR), your doctor must assess the concentration of creatinine in your urine. Creatinine, a byproduct generated by muscle cells, is excreted as waste. However, if your kidneys are not functioning optimally, creatinine may build up in your bloodstream.

What is it Used For?

A GFR test helps to:

• Efficiently detect the existence of chronic kidney disease, regardless of the presence of symptoms.
• Evaluate the extent of severity associated with the kidney disease.
• Effectively implement adjustments to the treatment regimen of individuals with chronic kidney issues.
• Recommend medications that have minimal adverse effects on renal function.
• Prioritise the assessment of kidney health before initiating any intervention.

Why Do I Need a GFR Test?

The absence of symptoms may be observed if you find yourself in the initial phases of kidney disease. However, the eGFR test serves as a valuable tool in monitoring the health of your kidneys during routine checkups. By undergoing this test, individuals can identify the presence of any potential kidney diseases that may manifest in the future.

You may be at risk if you're:

• Living with diabetes
• Suffering from high blood pressure
• Having a medical history of diabetes, blood pressure or heart disease
• A heart disease patient
• Over 50 years of age
• Smoking frequently
• Overweight

Moreover, if you find yourself in the advanced stages of a chronic kidney disease, you may observe the manifestation of additional symptoms:

• Chronic inflammation in legs, hands, face, ankle, and feet.
• An urge to urinate more often
• Dry, itchy or scaly skin
• Continuous fatigue
• Muscle cramps
• Endless vomiting or nausea feeling
• Loss of appetite

What Happens During a GFR Test?

For the test, the lab technician will take a sample of your blood from your arm. A needle is inserted, and blood will be collected in a vial. During the process, you might feel a stinging sensation for a few minutes.

Will I Need to Do Anything to Prepare for the Test?

Depending on the nature of the test, your doctor may recommend fasting for a certain period before the test. Additionally, it is crucial to inform your doctor about any medications you are currently taking for their guidance.

Your doctor may also suggest you avoid consuming meat the night before the scheduled test, as it can raise the creatinine level in your blood, potentially impacting the accuracy of the GFR results.

Are there Any Risks to the GFR Test?

The GFR test involves the insertion of a needle into a vein to collect blood samples. Although this is a routine procedure, it carries a small risk of infection, bleeding, or bruising at the injection site.

What do the Results Mean?

If the values are low in your GFR test, it indicates the presence of a kidney disease. By looking at the GFR levels, your doctor can discern the extent of kidney impairment, thereby facilitating an accurate diagnosis.

Here are some of the causes of low GFR:

• Hypertension
• Diabetes
• Various types of vascular diseases
• Inflammatory conditions like lupus
• Polycystic kidney disease

It is important to note that kidney damage manifests in five distinct stages:

• Stage 1: This is when your GFR level is 90 or above. It is also known as the eGFR test normal range. There is no kidney damage at this stage.
• Stage 2: When the GFR level is 60-89, there is minimal damage to the kidney functioning at this stage.
• Stage 3: When the GFR level is 30-59, it means that there is moderate damage in the kidney functioning at stage 3.
• Stage 4: When your GFR level is 15-29, it signifies severe damage to your kidney.
• Stage 5: When your GFR level is below 15, it is a sign of kidney failure. You might need a kidney transplant at this stage.

If you're wondering what is the normal GFR for age 60, the answer would be 85 ml/min/1.73m². This is considered within the normal range for this age group. It can vary depending on various factors such as overall health, medical history, and lifestyle choices.

Conclusion

Regular check-ups, maintaining a healthy lifestyle, managing blood pressure, and staying adequately hydrated are essential for promoting optimal kidney function as you age. If any signs of low GFR or symptoms of kidney disease are observed, you must contact your doctor. Additionally, it is essential to seek the services of a reputable diagnostic centre to obtain an accurate GFR blood test result.

Being a complicated test, the GFR test needs a reliable pathology lab like Metropolis Labs. Metropolis is a renowned and trusted diagnostic company in India. Reach out to your nearest Metropolis Lab or visit the website for a GFR test.