Two thirds of people with suspected acid reflux do not have the condition, according to a study.
Up to 10 million adults in the UK are thought to be taking medication for persistent acid reflux, known as gastro-oesophageal reflux disease (GORD), which causes heartburn, bloating and pain when swallowing.
Symptoms are usually managed using a prescription medication to reduce stomach acid production, which can have damaging long-term consequences. Some sufferers undergo invasive surgery to prevent the backflow of stomach acid.
However, research by the Functional Gut Clinic found that 66 per cent of people with suspected acid reflux had normal levels of acid exposure and therefore did not have the condition.
Experts said the majority of people who thought they had acid reflux probably had other conditions, such as Small Intestinal Bacterial Overgrowth (SIBO), functional heartburn or oesophageal hypersensitivity.
Scientists tested more than 700 people across six NHS trusts who were on medication for acid reflux. They found that only a third met the criteria for a diagnosis of the condition, while the others were probably suffering from other conditions.
The NHS does not routinely test all acid reflux patients, with only one in 12 patients getting a test, and only if the drugs are not working. The test involves putting a catheter through the nose and down into the stomach to test acid levels.
The study suggests that about six million people who take medication for acid reflux in the UK do not have the condition, and are therefore taking the drugs unnecessarily and need a different treatment.
Prof Anthony Hobson, the Functional Gut Clinic’s director, said: “It suggests that there could be a significant number of patients in the UK who have been misdiagnosed with GORD.”
Heartburn – a burning sensation in the middle of your chest – and an unpleasant sour taste in the mouth are the main symptoms of acid reflux, when stomach acid rises towards the throat.
NHS guidance recommends that patients speak to a GP about heartburn if over-the-counter medication and lifestyle changes do not provide relief. The vast majority are then prescribed acid-blocking drugs known as proton pump inhibitors (PPIs).
Under National Institute for Health and Care Excellence (Nice) guidelines, reflux testing is generally reserved for patients who have failed an initial trial of PPIs, which block an enzyme responsible for stomach acid secretion.
Yet some NHS trusts face testing backlogs of more than a year, leaving patients reliant on repeated courses of the medication to stave off symptoms. An estimated five to 10 million people are prescribed PPIs each year, costing the NHS about £190m annually.
Prof Hobson said that for many, PPIs had become a “patch-over” to reduce symptoms but also remove 80 per cent of stomach acid. This could have “profound effects” on the gut’s microbiome, raising the risk of stomach infections in those without excess acid production, he said.
He added that relying on medication encouraged people not to change their lifestyles if they were overweight or drank too much alcohol, which were major drivers of acid reflux.
Prof Hobson said: “Millions of people have these symptoms and the effects they have on quality of life, workplace absenteeism and longevity can be devastating.
“If you can pinpoint the reasons and get an effective treatment so that reflux is no longer causing symptoms or damage, that can have a huge impact.”
Dr Paul Goldsmith, a gastrointestinal surgeon at Manchester University NHS Foundation Trust, said about 15 per cent of patients with confirmed GORD had underlying conditions such as a hernia, which may be better managed with surgery rather than long-term PPI medication.