Start with a phone call. Your doctor’s office has a triage line and a nurse will talk it through with you. They are genuinely good at this, they do it all day, and it costs nothing. Most practices have a phone line where a nurse takes calls about whether something needs to be seen, and how soon. It is often not advertised — you ring the main number and ask to speak to the triage nurse. There is no charge and you do not need an appointment to use it.
If it feels more serious than that, go to urgent care. You will usually be seen faster than at a hospital, and the care is good.
If it feels life-threatening, call 911 or go to the emergency room. Do not wait until you are sure.
Which one is yours to decide, not ours. But our advice is to assume it is worse than it looks and take the more cautious road. And trust your body — if it is telling you something is wrong, it is probably right. The best possible outcome of a trip to the emergency room is walking out saying well, that was a waste of an evening — but I feel a lot better knowing it is nothing serious.
Before you call, have these ready. They are what the nurse will ask, and the call goes better when you are not working them out on the phone.
You are not diagnosing yourself by having this ready. You are handing them the things they would otherwise spend the call extracting — and the decision stays entirely theirs.
Writing to the portal instead of calling? The same list works, in that order, in one message. Put the direction it is going and the immune-system line near the top — portal messages get read quickly, and those two change how the rest is read.
One of the things people type into Google most is what is a normal eGFR for my age
.
The honest answer is: normal compared to whom? Your own number from last year tells you more than any table. This room is about reading the trend, not the threshold.
The short answer, before anything else.
eGFR is an estimate, not a measurement. It is calculated from creatinine, which comes from muscle. So it is answering a question about your kidneys using a number that also depends on how much muscle you are carrying.
A steady creatinine is not the reassurance it looks like. If muscle is being lost at the same time as kidney function, the two move in opposite directions and the number can sit still while things change underneath it.
Results from different years may not be comparable. Laboratories change the equation they use. A series that crosses one of those changes is two records, not one line.
The one thing to do next: Worth asking: “Would Cystatin C tell us something different? It does not depend on lean body mass.” and “Could we look at these in date order rather than one at a time?”
Everything below explains each of those, in whatever order suits you.
None of those? Then nothing below is an emergency, and you can read the rest calmly.
The frail eighty-year-old with the beautiful creatinine.
A result that looks steady may not be.
A steady Creatinine result here is not the reassurance it looks like. It has barely moved — but Lean Body Mass is down 2% over the same stretch, and muscle makes creatinine.
Worth asking: “Would Cystatin C tell us something different? It does not depend on Lean Body Mass.”
A steady CK result here is not the reassurance it looks like. It has barely moved — but Lean Body Mass is down 2% over the same stretch, and CK is a muscle enzyme.
Muscle makes creatinine. The kidney clears it. Lose muscle and you make less of it. Lose kidney and you clear less of it. The number sits still while both are going wrong.
The kidney estimate assumes your muscle is average for your age and sex. When it isn't, the estimate carries that error forward. The fix is a marker your muscles don't make. Cystatin C is the usual one. The same trap turns up wherever a marker's source is fading. Albumin drops when someone stops eating well, not only when the kidney leaks. CK drops as muscle disappears, not only when injury stops. Urea depends on how much protein went in.
Before you read any trend, ask what makes this substance and whether that thing is changing too. If it is, a flat line means nothing and you need a second marker with a different source.
Baxmann AC et al. Influence of muscle mass and physical activity on serum and
urinary creatinine and serum cystatin C. Clin J Am Soc Nephrol. 2008.
Shlipak MG et al. Cystatin C versus creatinine in determining risk based on
kidney function. N Engl J Med. 2013.
Her liver numbers improved when she changed hospitals. Her liver didn't.
Some of your results may not be comparable with each other.
AST came back 200.0 from Tufts on 2024-11-18, and 370.0 from SVMC on 2024-11-22 — 85% apart, days apart.
AST came back 24.0 from SVMC on 2023-06-24, and 21.0 from Tufts on 2023-06-26 — 12% apart, days apart.
AST came back 21.0 from Tufts on 2023-06-26, and 27.0 from SVMC on 2023-06-29 — 29% apart, days apart.
AST came back 25.0 from SVMC on 2023-07-03, and 19.0 from Tufts on 2023-07-05 — 24% apart, days apart.
AST came back 23.0 from Tufts on 2023-09-12, and 28.0 from SVMC on 2023-09-14 — 22% apart, days apart.
AST came back 31.0 from SVMC on 2024-04-18, and 24.0 from Tufts on 2024-04-22 — 23% apart, days apart.
AST came back 25.0 from UIMC on 2024-10-04, and 39.0 from SVMC on 2024-10-07 — 56% apart, days apart.
Albumin came back 3.9 from Tufts on 2024-04-22, and 4.49 from DHMC on 2024-04-22 — 15% apart, days apart.
Albumin came back 3.9 from SVMC on 2024-11-22, and 3.4 from Tufts on 2024-11-25 — 13% apart, days apart.
Albumin came back 3.4 from Tufts on 2024-11-25, and 3.8 from SVMC on 2024-11-27 — 12% apart, days apart.
Albumin came back 3.9 from RRMC on 2026-03-26, and 4.4 from DHMC on 2026-03-27 — 13% apart, days apart.
CK came back 4650.0 from Tufts on 2024-11-18, and 6650.0 from SVMC on 2024-11-22 — 43% apart, days apart.
Creatinine came back 1.66 from Tufts on 2023-06-26, and 2.1 from SVMC on 2023-06-28 — 27% apart, days apart.
Creatinine came back 1.5 from SVMC on 2023-06-24, and 1.66 from Tufts on 2023-06-26 — 11% apart, days apart.
Creatinine came back 1.66 from Tufts on 2023-06-26, and 1.9 from SVMC on 2023-06-29 — 14% apart, days apart.
Creatinine came back 1.22 from UIMC on 2024-10-04, and 1.4 from SVMC on 2024-10-07 — 15% apart, days apart.
Creatinine came back 1.2 from SVMC on 2024-11-22, and 1.32 from Tufts on 2024-11-23 — 10% apart, days apart.
Creatinine came back 1.2 from SVMC on 2024-11-22, and 1.05 from Tufts on 2024-11-25 — 12% apart, days apart.
Creatinine came back 1.05 from Tufts on 2024-11-25, and 1.2 from SVMC on 2024-11-27 — 14% apart, days apart.
Worth asking: “Are these comparable, or should I treat them as separate records?”
Two labs can run the same test on the same blood and get different answers. They use different machines, calibrated differently, with their own idea of normal. Nobody reconciles them, because no single lab ever sees the other one's numbers.
Each lab is internally consistent, so each one looks trustworthy on its own. The error only appears when you line them up, and lining them up is something only the patient is in a position to do. Watch for two shapes. A step in the level exactly where care moved. And two results days apart from different labs that disagree by more than the body could possibly move in that time.
A series is only a series if the same ruler measured all of it. Where the ruler changes, treat the step as an artefact until something proves otherwise.
Standardisation of body composition parameters between GE Lunar iDXA and
Hologic Horizon A and their clinical impact. 2024.
Direct observation: in one longitudinal record, AST averaged 38.7 at one
hospital and 19.8 at another over overlapping years, same patient.
Normal every year for nine years. Then stage four. Nothing was ever abnormal — it was just always a little worse than last time.
Every one of these was normal, and every one of them was moving.
Every one of your Albumin results from DHMC came back inside the normal range (3.50 - 5.10 g/dL) — 30 of them. Over that stretch the number went from 3.87 to 4.6.
Worth knowing: DHMC did not use one range across those results. It used 3.50 - 5.10 g/dL and then 3.2 - 5.2 g/dL. The same number can sit inside one and outside the other.
Which direction is the worrying one for this test has not been settled here, so this is movement, not bad news.
Worth asking: “Could we look at these in date order rather than one at a time?”
A normal range is built from a crowd. It says whether you look like other people. It cannot say whether you are moving, or how fast, or which way. Someone whose usual number is at the low end can lose a third of their function and still land inside the range every single time.
Almost every alert in medicine fires on a threshold. Cross the line, something happens. Stay inside it and nothing does. So a person sliding steadily downhill inside the range triggers nothing, year after year, and each visit ends with good news that was true and useless. The direction and the speed carry the information. The position carries almost none.
Ask of any result: compared with this person's own past, which way and how fast? A number is a dot. Two dots are a difference. Only many dots are a direction.
KDIGO defines chronic kidney disease by abnormality persisting over three
months — the criterion is duration, not a single value.
Roughly nine in ten adults with chronic kidney disease do not know they have it.
When to worry
What you can do yourself
What your results mean
The things that are awkward to ask
Print this, or post it to your portal the night before. It is not a diagnosis and it does not ask anyone to accept anything.
What I noticed
my rings don't fit
What I would like to ask
This may not belong to one person
Swelling can come from the kidney, the heart or the liver, and each one makes the others worse. Whoever sees it first is the right person to start asking.
Could matter to: kidney, heart, liver
Muscle loss makes kidney results look better than they are, and it changes how drugs should be dosed. It matters to more than one of my doctors.
Could matter to: kidney, cancer care, nutrition, physical therapy
This page does not diagnose anything and does not replace your doctor. It reads your own records back to you and suggests questions. Nothing you type here leaves your device.