Lab results explained
eGFR Explained: What Your Kidney Function Number Means
eGFR, estimated glomerular filtration rate, is a number calculated from a blood test that shows how well your kidneys filter waste. It usually comes with your creatinine result. A lower eGFR means the kidneys are filtering less, but one low reading does not mean kidney disease. This guide explains the stages and what is checked next.
Part of Kidney, liver and inflammation tests
Typical ranges at a glance
- Normal or high
- 90 or higher (mL/min/1.73 m²)
- Mildly decreased
- 60 to 89, often normal with age unless there are other signs of kidney damage
- Mild to moderate decrease (stage 3a)
- 45 to 59
- Moderate to severe decrease (stage 3b)
- 30 to 44
- Severe decrease (stage 4)
- 15 to 29
- Kidney failure (stage 5)
- Below 15
Chronic kidney disease is diagnosed only when eGFR stays below 60, or there are other signs of kidney damage such as albumin in the urine, for at least three months. Always use the reference range printed on your own report.
What is eGFR?
Your kidneys filter waste and extra fluid from the blood through millions of tiny filters called glomeruli. eGFR estimates how much blood they filter each minute. It is calculated from your blood creatinine level together with your age and sex, and sometimes from another marker called cystatin C. Most labs now use equations that do not include race.
Why one low result is not a diagnosis
eGFR can drop for a short time with dehydration, a recent large meat meal, intense exercise, illness and some medicines, including anti-inflammatory painkillers. Very muscular people can have a falsely low eGFR, and people with low muscle mass a falsely high one. That is why a low result is usually repeated, and chronic kidney disease is only diagnosed when it stays low for three months or more.
eGFR and urine albumin together
Clinicians look at kidney health with two tests: eGFR, which shows filtering, and the urine albumin-to-creatinine ratio (ACR), which shows whether protein is leaking into the urine. An ACR above 30 mg/g (3 mg/mmol) is a sign of kidney damage even when eGFR is normal. Together they set the stage of kidney disease and guide how often to recheck.
Common reasons for a lower eGFR
The most common long-term causes are diabetes and high blood pressure. Others include kidney inflammation, polycystic kidney disease, repeated kidney infections, blockages and long-term use of some medicines. eGFR also tends to fall slowly with age, so a reading between 60 and 89 in an older adult may be normal if there are no other signs of kidney damage.
When a low or falling eGFR needs quick follow-up
A sudden drop in eGFR, a result below 30, or a low eGFR with symptoms such as much less urine, swelling of the legs or face, breathlessness, confusion or nausea needs prompt medical care. A steady fall over several tests, even within the normal range, is also worth discussing with your clinician.
How to protect your kidneys
Keeping blood pressure and blood sugar in your target range is the most important step. Not smoking, staying active, keeping a healthy weight, limiting salt and avoiding regular use of anti-inflammatory painkillers also help. Some blood pressure and diabetes medicines also protect the kidneys; whether you need one is a decision for you and your clinician.
Frequently asked questions
Is an eGFR of 60 bad?
An eGFR of 60 is at the border of the mildly decreased range. On its own it is not a diagnosis of kidney disease, especially in older adults. Your clinician will usually repeat it, check urine albumin and look at your blood pressure and blood sugar.
Can eGFR improve?
Yes, it can. A low reading caused by dehydration, illness or a medicine often returns toward normal once the cause is fixed. In long-term kidney disease, the aim is usually to slow or stop the decline, which good blood pressure and blood sugar control can do.
Does drinking more water raise eGFR?
If you were dehydrated, drinking enough fluid can bring a temporarily low eGFR back up. Drinking far more than you need does not improve kidney function, and people with advanced kidney disease may be advised to limit fluid.
What is the difference between creatinine and eGFR?
Creatinine is a waste product from muscles that the kidneys clear from the blood. eGFR is calculated from creatinine, age and sex to estimate filtering. A higher creatinine usually means a lower eGFR.
Understand your eGFR next to the rest of your health
Add your results to VHT and see eGFR alongside your other labs, symptoms and history, and ECHNA, your AI health assistant, explains what changed in plain language.
