Prompt action can save your kidneys if you suffer from acute kidney injury, which can appear suddenly says Dr Mel Wynne-Jones

When your kidneys stop working

Acute kidney injury (sudden damage/AKI) usually develops during serious illness or in older people with long-term medical problems.

Around one in five of those admitted to hospital has AKI, but up to 30% of the 100,000 who die each year could be saved by treatment, says a new campaign

AKI is an emergency so hospitals must now send GPs electronic alerts if a patient’s kidney function suddenly deteriorates. So you could get a call after a routine blood test (though it may be a false alarm).

What kidneys do

These bean-shaped, fist-sized organs sit in our backs at waist level. They filter blood and adjust body fluids and chemicals by excreting waste products, toxins, drugs and excess water into urine. They also regulate blood pressure and produce vitamin D for healthy bones as well as erythropoietin, which stimulates red blood cell production.

Who’s at risk?

Chronic renal failure (slow, often unnoticed, deterioration) is more common than AKI. It’s linked to age, lifestyle, cardiovascular (arterial) disease, high blood pressure, diabetes, urinary blockages (stones, prostate problems) and kidney disease, and some drugs, including non-steroidal anti-inflammatory drugs such as ibuprofen.

But it makes you more vulnerable to conditions that trigger AKI, such as dehydration, infection (pneumonia, sepsis), shock (trauma, heart attacks, surgery), acute urinary blockages, kidney disease or medication.

Your symptoms

There may be none in the early stages, although they can then develop rapidly.  Filtration rates fall steeply, and you may pass less than 500ml of red/brown urine a day (or none). As fluid and waste products build up, you’ll feel tired, nauseated, itchy, lack concentration and develop swollen ankles and fingers or breathlessness. Without any treatment other organs will fail.

Tests you’ll need

Blood tests will show rising levels of waste product creatinine, reflecting a drop in filtration; blood acidity, sugar and potassium levels will rise. Urine may show blood, protein, sugar or infection.

Blood and urine will be continuously monitored for signs of deterioration or improvement but you may need other tests, scans and/or X-rays to track down the cause.

Your treatment

There’s no drug or cure – AKI treatment is aimed at the cause (such as antibiotics for sepsis, stopping damaging drugs or removing urinary obstructions) and supporting the body by avoiding fluid overload and adjusting abnormal chemicals.

In severe cases, dialysis to ‘cleanse’ blood may be needed. Haemodialysis uses a machine to filter blood, while peritoneal dialysis ‘washes out’ toxins. Some people may need renal replacement therapy (dialysis or a transplant) but AKI may be fatal in more than a quarter of cases, so prevention is best.

5 tips to protect your kidneys

1. Don’t smoke, and maintain a healthy weight to protect arteries and reduce risk of diabetes or high blood pressure.

2. If you already have these conditions, or other signs of chronic kidney damage, make sure they’re controlled and you have annual kidney checks.

3. If you don’t have these, get a blood pressure and diabetes check every five years.

4. Have any urinary symptoms checked out early.

5. If you already have kidney disease, contact the British Kidney Patient Association (01420 541 424;