As many as one in three diabetes inpatients have been affected by NHS mistakes, according to a new report.
A study carried out by Diabetes UK Cymru found that while the number of people with diabetes in Wales rose by more than a quarter in five years, many are experiencing errors.
Diabetes UK Cymru director Dai Williams told the BBC Wales Week In Week Out programme that the cost of diabetes care is "massive", describing it as a "ticking timebomb".
"We've got people wandering around with high blood sugars, not even realising it's going to cause a problem," he was quoted as saying by the news provider.
Councillor Elizabeth Evans, a senior case worker for Mark Williams MP, explained complaints have been made over a range of issues with care, including fluid intake and patients not eating properly.
According to a recent study published in the Endocrine Society's Journal of Clinical Endocrinology & Metabolism, people who have been diagnosed with diabetes are more likely to develop hearing problems later in life.
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