NSAIDs and acute kidney injury: who is at risk and what to do

The NHS describes acute kidney injury (AKI) as when something suddenly causes your kidneys to stop working as well as they should, and says it can be very serious for some people. Lots of things can cause it, from infection and dehydration to blockages and certain medicines. NSAIDs are one such trigger.

Kidney Care UK, a UK kidney charity, explains in a March 2026 statement with the National Pharmacy Association that NSAIDs increase blood pressure and cause damage to the blood vessels inside the kidneys. It stresses that NSAIDs such as ibuprofen are effective and safe medicines for many people, but that patients should be aware of their impact, particularly if they are at increased risk of kidney disease, and consider alternatives where appropriate. It is the combination of the drug, the dose, how long it is taken and the person's own risk factors that matters.

The NHS says anyone can get AKI but it is more common if you are 65 or older, have had AKI before, have recently had surgery or take illegal drugs. It also lists dehydration, low blood pressure or blood loss, infection or sepsis, long-term conditions of the kidneys, heart or liver, and the dye used in some scans among causes.

On the medicines side, the NHS names anti-inflammatory medicines (NSAIDs), ACE inhibitors and diuretics together as medicines that can cause AKI with long-term use. The NHS ibuprofen page adds that ibuprofen may not be suitable if you have a heart, liver or kidney condition or problems with blood clotting. Kidney Care UK reports that about one in four people who completed its Kidney Health Checker regularly use over-the-counter pain relief, and that about three quarters of people with chronic kidney disease said they were unaware before diagnosis that NSAIDs could harm kidney function if used long term or in high doses.

The NHS notes that many people have no symptoms of AKI, especially if it is mild. When symptoms occur they may include the following.

• Peeing a lot less than usual.

• Feeling very thirsty.

• Feeling or being sick.

• Swollen feet or legs.

• Feeling tired, dizzy, confused or sleepy.

• Feeling breathless, especially when lying down.

The NHS says to ask for an urgent GP appointment or get help from NHS 111 if you think you may have symptoms of AKI. The NHS ibuprofen page lists kidney problems, with symptoms such as shortness of breath, blood in your pee or swelling in your ankles, feet or legs, among the possible serious side effects. Do not wait for symptoms to settle on their own, and do not keep taking an anti-inflammatory painkiller while you are being assessed unless a clinician tells you to. If you are very breathless, confused or unable to pass urine at all, call 999 or go to A&E.

According to the NHS, AKI is diagnosed using a blood test that measures creatinine, a waste product made by muscles and removed by the kidneys. Higher than usual levels mean the kidneys are not working as well as they should. A doctor may also ask for a urine sample, check pulse and blood pressure, and arrange an ECG or scans such as an X-ray, CT or ultrasound. If AKI is severe or the cause is unclear, referral to a kidney specialist or admission to hospital may follow.

Treatment depends on severity and cause. The NHS lists medicines to treat infection or raise blood pressure, stopping or changing any medicine that could be causing damage to the kidneys, fluids given by a drip, a catheter to drain urine and surgery to remove a blockage. If AKI is severe, dialysis can take over the work of the kidneys, usually for a few days or weeks until they recover.

The NHS says AKI is serious and can be life-threatening if not treated, but many people recover fully within a few weeks with no long-term effects; if it is more serious, recovery can take several months. Regular blood tests and check-ups follow to make sure the kidneys are working as expected. Some people have permanent damage and develop chronic kidney disease, more likely if the AKI was severe or other long-term conditions are present.

The NHS advice for people at higher risk is to stay hydrated, drinking enough that your pee is pale and regular, especially in hot weather or when being sick or having diarrhoea; to speak to a doctor before taking any new medicines or supplements; and to know the symptoms of AKI. Kidney Care UK advises anyone concerned about their use of NSAIDs to speak to a pharmacist, who can help manage pain effectively.

AKI is diagnosed and treated by NHS GPs and hospitals, and over-the-counter NSAIDs can be discussed with a community pharmacist at no charge. Private blood tests may measure kidney function, but any abnormal result should be discussed promptly with a GP, because the NHS describes AKI as a condition where you should get medical help if you think you have it.