Empeiria

Long-term reduced kidney function

Clinically: Chronic kidney disease · also CKD, kidney disease, renal failure, reduced kidney function

renal ICD-10 N18.9 MONDO MONDO:0005300 unverified
This describes what this condition typically looks like. It is not a diagnosis and cannot tell you whether you have it -- patterns overlap, results vary between labs, and the same numbers mean different things in different people. Diagnosis usually rests on Estimated glomerular filtration rate, interpreted alongside symptoms and history rather than read off a report.

unverified These explanations are written to be easy to read and have not yet been checked against a source. The ranges and measurement notes on this page show theirs.

definition unverified

Your kidneys have been damaged, or have been filtering less than they should, for at least three months. It is graded by how much filtering capacity remains and how much protein leaks into your urine.

Abnormalities of kidney structure or function present for a minimum of 3 months, with implications for health: GFR <60 mL/min per 1.73 m2 and/or albuminuria (ACR >=30 mg/g [3 mg/mmol]) or other markers of kidney damage. It is classified by cause, GFR category (G1-G5) and albuminuria category (A1-A3).

caveats unverified

Filtering declines gently with age in everyone, so a modestly reduced number in an older person is often expected rather than alarming. What matters more is whether it is falling over time. The word "chronic" means long-standing, not severe -- a single abnormal result does not establish it.

Filtering declines gently with age in everyone, so a modestly reduced number in an older person is often expected rather than alarming. What matters more is whether it is falling over time. The word "chronic" means long-standing, not severe -- a single abnormal result does not establish it.

No clinical version written yet.

How common it is

Affects a substantial minority of adults, rising sharply with age. Diabetes and high blood pressure are the two leading causes.

The typical lab pattern

What the diagnosis rests on

The results a diagnosis is actually made on.

Estimated glomerular filtration rate low ref ≥ 60 Under the KDIGO definition, a GFR below 60 mL/min/1.73 m² for more than 3 months indicates CKD (a raised urine albumin can also define it).
Consistent with it

Fits the picture, but not enough on its own.

Creatinine high — Used to calculate eGFR, which is what the CKD definition uses. Creatinine rises as kidney disease gets worse.
Urea nitrogen high — One of the tests used to check how well the kidneys are working.
Followed over time

Tracked once it is established.

Potassium high — Checked regularly as kidney disease worsens; high potassium is a known complication.
Phosphate high — Checked regularly from CKD stage G3a onward; high phosphate is a known complication.
Calcium, total low — Checked regularly from CKD stage G3a onward. A low calcium is a classic feature of untreated CKD.
Hemoglobin low — Anaemia is a common complication, and becomes more common as kidney function falls; blood counts are checked regularly.

How it usually feels

Frequencies say how often a symptom accompanies this condition — not the other way round. Most people with any of these symptoms do not have this.