IgA nephropathy (IgAN)
IgA nephropathy is the world’s most common primary kidney inflammation.
An antibody called IgA builds up in the kidney’s filters and inflames them. It is often found late — after years of quiet blood and protein in the urine that were noticed and not chased.
Go deeper
3 layers below. Open any one.The classic tell is visible blood in the urine at the same time as an infection — a sore throat or cold on the same day, not a week later. (Blood a week or two after a throat infection points instead at a different, post-infection kidney problem.) Just as often there are no symptoms at all, and it shows only as microscopic blood and a little protein on a routine test.
“A bit of blood in the urine” gets watched rather than worked up, and the disease is slow, so years can pass. The diagnosis is made on a kidney biopsy showing IgA deposits in the filters. Blood and protein in the urine, and the eGFR trend across years, are what is followed.
The course is very variable — some people never progress, others slide toward kidney failure over years. Strong evidence The two things that predict and track it are how much protein is spilled and the eGFR trend — which is why lowering protein is the core of treatment: blood-pressure control with an ACE inhibitor or ARB, and increasingly an SGLT2 inhibitor. Good evidence Newer targeted options (a gut-released steroid, and complement-pathway drugs) are arriving fast — ask what is available now or in a trial. See CKD for the trend-not-threshold point.
Questions to bring
Copy these, or read them out. They fit in a short visit.
- Was the blood in my urine timed with an infection?
- How much protein am I spilling, and what is the trend?
- Is my blood pressure optimised, and am I on an ACE/ARB — and an SGLT2 inhibitor?
- Given my risk, are newer targeted treatments or a trial worth considering?
The short version
- Getting ahead of it
- Control blood pressure and protein early (ACE/ARB, and increasingly an SGLT2 inhibitor); track the trend.
- Your testing regime
- Urine protein quantification, the eGFR trend across years, and a kidney biopsy for the diagnosis.
- What they don’t tell you
- Proteinuria and the trend predict the course more than any single value — and newer targeted drugs are arriving fast.
- What it can spawn
- Progressive chronic kidney disease and failure over years.
- What it’s confused with
- A harmless “bit of blood in the urine,” and post-infectious kidney disease (the timing differs — same day, not a week later).
General clinical literature; not a diagnosis, and nothing here comes from any individual’s medical record.