What's this test for?

This test is ideal if you're experiencing swelling in your legs or ankles, changes in urination, fatigue, or unexplained high blood pressure. It's also a good fit if you have diabetes, a family history of kidney disease, or just want to check how well your kidneys are filtering waste from your blood. Catching kidney problems early can help you make changes before they become serious.

How should I prepare for this test?

How can I naturally support my kidney health? Staying well hydrated, cutting back on excess salt and processed foods, and limiting alcohol can all help your kidneys work more efficiently. Regular exercise and keeping blood pressure and blood sugar in a healthy range also protect kidney function over time. If you take over-the-counter pain relievers regularly, cutting back may reduce extra strain on your kidneys.

What's included in this test?

This test combines two different kidney markers to give you a more accurate picture than either one alone. Creatinine reflects muscle waste your kidneys filter out, while Cystatin C is less affected by muscle mass or diet, making the combined result more reliable, especially for people of different body types and backgrounds.

What happens after I get my results?

Your results will be available in your account, with each value's normal range clearly explained. If your kidney function score is lower than expected, simple next steps like drinking more water, cutting back on salt, or reducing certain medications can help, and retesting every few months lets you see if things are improving. If any value comes back dangerously low, the report will flag that you should seek medical care right away. You can download a standard lab report from your account anytime and track your kidney health over time using the trends feature.

When will I get my results?

Results are typically ready within about 7 days of your sample being collected. Once processed, they'll show up automatically in your online account, and you'll be able to see each marker along with what the numbers mean.

Who should consider this test?

People with diabetes, high blood pressure, or a family history of kidney disease are good candidates for this test. It's also worth considering if you're over 60, take medications that affect the kidneys, or have noticed changes in how often or how much you urinate. Anyone wanting a baseline check of their kidney health can benefit too.

What symptoms indicate I may need this test?

Swelling in your feet, ankles, or hands, feeling unusually tired, foamy or dark urine, and needing to urinate more or less than usual can all be signs your kidneys need a check. Muscle cramps, poor appetite, and trouble concentrating are less obvious signs that sometimes point to kidney issues too. If you notice several of these together, this test can help clarify what's going on.

What does low eGFR mean?

A low eGFR score means your kidneys aren't filtering waste from your blood as efficiently as they should. This can happen gradually with age or health conditions like diabetes and high blood pressure, or it can signal a more immediate problem. Simple changes like drinking more water, lowering salt intake, and managing blood pressure can help, and retesting helps track whether the number is improving or getting worse.

What causes low eGFR?

Common causes include long-term high blood pressure, diabetes, dehydration, certain medications like some pain relievers, and natural age-related decline in kidney function. Less commonly, infections or blockages in the urinary tract can also lower this number temporarily. Identifying and addressing the underlying cause is the most effective way to protect your kidneys going forward.

How often should I retest?

If your results are within a normal range and you have no risk factors, checking again once a year is usually enough. If your eGFR is borderline or you have diabetes, high blood pressure, or other risk factors, retesting every 3 to 6 months gives you a better sense of any trend. Tracking your results over time is more useful than looking at a single number.

Getting your blood test with us is easy, private & backed by the power of science.Long story short: In the test options, use the filters or search box to narrow your choices and find the test you want. If you need a hand navigating through options, text our super friendly support team at 754-799-7833, and we'll provide tailored suggestions to help you find the ideal test. Once your order is placed, we’ll create your doctor’s lab order remotely, without any need for you to make a trip to a doctor in person or to talk to the doctor. Expect to receive your doctor’s lab order right in your inbox. It will also be in your patient portal if you need to find it later. We’ll also include instructions regarding fasting and other requirements for your test. Your patient portal will be auto-created hassle-free during checkout. If this is your first time ordering, you'll be prompted to create a password for instant login access to your patient portal. It's a quick way to conveniently access your orders and results whenever you want. When you’re ready, visit one of our 4,000 locations. Just bring your ID – no printing or faxing of your lab order is needed, as your order and details will already be in the lab system. Note that most lab locations don’t accept walk-ins, so it’s best to book an appointment in advance. Don’t worry – we’ll provide detailed instructions along the way. You’ll get your results via email & SMS and dive into understanding your body better. Yup, that easy! If you have any questions, please text us at 754-799-7833 or email support@privatemdlabs.com and we'll gladly help you.

How do I know which test to get?

In the test options, find the test you want. If you’re not sure which test to get, we can lend a hand in finding the right option. Just text or call us at 754-799-7833, email us at support@privatemdlabs.com, and we'll gladly help you. We've got your back and reply quickly.

When will my lab results be available?

Most test results will be available within 1–3 business days. Once they're ready, we'll send an email and text message to let you know. After your blood draw, just hang tight and don't worry – we'll keep you updated and in the loop! If you have any further questions, please text us at 754-799-7833 or email support@privatemdlabs.com, and we'll gladly help you.

Is it possible to make changes to my lab order if I made a mistake with the name, date of birth, or any other details?

Absolutely! We totally understand that errors can happen. No worries, we're here to help you. Just reach out to us via text at 754-799-7833 or shoot us an email at support@privatemdlabs.com. Remember to include your order number and let us know the correct information you’d like to update. Our awesome team will jump right in and make sure everything is sorted out and accurate for you. There are no changes necessary if your address is wrong on the requisition though. We don’t mail anything out. Our lab requires an address to be listed to generate an order.

Do you accept health insurance?

Only HSA & FSA is accepted. Our services are strictly self-pay and cannot be submitted to your health insurance provider except for Health Savings Accounts or Flexible Savings Accounts. This policy applies to all insurance companies, including federal health insurance programs like Medicare. If you have any questions, please text us at 754-799-7833 or email support@privatemdlabs.com.

Can I cancel my order?

Yes. We get it – sometimes your needs change. As long as your samples haven’t been collected yet, we’re happy to help you cancel your order. If you have any further questions, please text us at 754-799-7833 or email support@privatemdlabs.com. You can read more about our cancellation policy here.

How can I find a lab location near me?

During the ordering process, you’ll be able to select a specific lab near you, with no strings attached! You can switch it up later easily and visit any of our authorized locations as long as it’s the same lab company you selected your test for (Quest Diagnostics or Labcorp). Before you proceed with your order, feel free to browse through all our lab locations here. This will give you the peace of mind of knowing that there's a lab nearby your home, office or your favorite gym. If you have any questions, please text us at 754-799-7833 or email support@privatemdlabs.com and we'll gladly help you.

eGFR Kidney Function Test - Creatinine & Cystatin C

Getting your blood test with us is easy, private & backed by the power of science.

Long story short:

In the test options, use the filters or search box to narrow your choices and find the test you want.
If you need a hand navigating through options, text our super friendly support team at 754-799-7833, and we'll provide tailored suggestions to help you find the ideal test.
Once your order is placed, we’ll create your doctor’s lab order remotely, without any need for you to make a trip to a doctor in person or to talk to the doctor. Expect to receive your doctor’s lab order right in your inbox. It will also be in your patient portal if you need to find it later. We’ll also include instructions regarding fasting and other requirements for your test. Your patient portal will be auto-created hassle-free during checkout.
If this is your first time ordering, you'll be prompted to create a password for instant login access to your patient portal. It's a quick way to conveniently access your orders and results whenever you want.
When you’re ready, visit one of our 4,000 locations. Just bring your ID – no printing or faxing of your lab order is needed, as your order and details will already be in the lab system.
Note that most lab locations don’t accept walk-ins, so it’s best to book an appointment in advance. Don’t worry – we’ll provide detailed instructions along the way.
You’ll get your results via email & SMS and dive into understanding your body better. Yup, that easy!

754-799-7833

[email protected]

Kidney Function Test — eGFR with Creatinine & Cystatin C

Estimated Glomerular Filtration Rate (eGFR) with Creatinine and Cystatin C

Prescription & all lab fees included

Doctor's guidance included

Fast & convenient

Prescription & all lab fees included

Doctor's guidance included

Fast & convenient

What's this test for?

How should I prepare for this test?

What's included in this test?

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Kidney Function Test — eGFR with Creatinine & Cystatin C

Prescription & all lab fees included

Doctor's guidance included

Fast & convenient

1,000,000+ blood tests later, here's what our customers say