Kidneys: quiet organs worth protecting

Your kidneys filter your entire blood volume many times a day, removing waste and keeping the balance of water, salt and minerals steady. They also help regulate blood pressure and prompt the making of red blood cells.

It is a considerable amount of work for two organs the size of a fist, and they do it without ever announcing themselves.

This is the important part. Kidney function can decline a long way before anything is felt, because the remaining tissue compensates. By the time there is tiredness, swollen ankles, breathlessness or a change in passing water, a good deal may already have been lost.

Which is why this is one of the conditions found by testing rather than by noticing, and why the checks matter even when you feel perfectly well.

High blood pressure and diabetes cause most kidney disease between them, both by damaging the small vessels doing the filtering. Keeping those two in hand is kidney protection, even though it never feels like it.

The everyday one is painkillers. Anti-inflammatory tablets taken regularly over long periods can harm kidneys, and they are easy to take for months for a sore knee without thinking of them as medicine. Worth asking your doctor or pharmacist if you use them often.

Blood pressure and blood sugar controlled. Less salt, mostly by cutting packaged food rather than the salt cellar. Enough water through the day. Not smoking. Care with regular painkillers.

And the tests: a blood test for kidney function and a urine test for protein, as often as your doctor advises. This is general guidance, not medical advice, and any concern about your kidneys belongs with your doctor.