eGFR 45 Meaning: CKD Stage 3a, Risks and Next Steps

An eGFR of 45 mL/min/1.73 m² falls in CKD stage G3a, the mild-to-moderate reduction range. It is an important result to follow, but one number does not prove chronic kidney disease. The result must be interpreted with repeat testing, urine albumin, age, medications, and medical history.

Use our CKD stage calculator to check any eGFR value, then discuss the full result with your healthcare provider.

What does an eGFR of 45 mean?

An eGFR of 45 means the estimated filtration rate is between 45 and 59. This is the G3a category. eGFR is an estimate based mainly on serum creatinine, age, and sex; it is not a direct measurement of kidney filtration.

Does eGFR 45 always mean CKD?

Usually, CKD requires an eGFR below 60 that persists for at least three months, or another marker of kidney damage. A single eGFR of 45 may be affected by dehydration, acute illness, recent intense exercise, dietary changes, or medicines that alter creatinine.

Your clinician may repeat creatinine and eGFR, order a urine albumin-to-creatinine ratio (UACR), check blood pressure, and review prescriptions. Trends are more useful than a single isolated value.

UACR is especially useful because eGFR and urine albumin describe different parts of kidney health. eGFR estimates filtration; UACR looks for albumin leaking into urine. Combining the G category with the albumin category gives more information about progression and cardiovascular risk than either number alone.

What should you do after an eGFR of 45?

1. Arrange follow-up rather than relying on an online result alone.
2. Ask whether repeat eGFR and UACR testing are needed.
3. Review NSAIDs, supplements, and all prescription medicines with a clinician or pharmacist.
4. Manage blood pressure, diabetes, smoking, and cardiovascular risk.
5. Avoid making sudden diet or medication changes without medical advice.

Before the visit, collect older laboratory results and note any illness, dehydration, intense exercise, creatine use, high-meat meal, or medication change around the test. This short timeline often provides more useful context than repeatedly recalculating the same result.

How eGFR 45 can mean different things

Can eGFR 45 improve?

It can improve when a temporary factor such as dehydration, infection, obstruction, or a medication effect is corrected. Established chronic kidney disease may not reverse, but careful treatment can slow further decline. Compare results over time with our free eGFR calculator, using the laboratory value and date for each test.

What not to conclude from one result

An eGFR of 45 does not reveal the cause, predict exactly how quickly kidney function will change, or determine a personal treatment plan. It also does not automatically require a restrictive “kidney diet.” Those decisions depend on urine tests, electrolytes, blood pressure, medicines, other illnesses, and individual goals.

This article is educational information, not a diagnosis or treatment plan. Seek medical care for symptoms or a rapidly changing kidney result.