Cases of diabetes in Wales are rising faster than previously predicted, according to new NHS figures which have prompted warnings of a growing public health challenge.

Data from StatsWales shows 230,371 adults aged 17 and over were living with diabetes in 2025 – a rise of 3.5% on the previous year and far ahead of earlier forecasts.

Public Health Wales had previously projected the number of diabetes cases would exceed 260,000 by 2035, but the latest trends suggest that figure could now be reached much sooner.

Health experts say around one in five adults in Wales is now living with either diabetes or pre-diabetes, while tens of thousands more people are thought to be undiagnosed.

Type 2 diabetes accounts for around 90% of all cases and is closely linked to obesity and deprivation. The condition disproportionately affects people from South Asian, Black African and Black Caribbean backgrounds.

A further 269,747 people in Wales are estimated to be living with pre-diabetes, where blood glucose levels are higher than normal but not yet high enough for a diabetes diagnosis.

Public Health Wales warned that if diabetes is left unmanaged it can lead to serious long-term complications including sight loss, kidney disease, nerve damage and cardiovascular disease.

The figures underline growing concerns over what campaigners have described as a “hidden crisis”, with increasing pressure on NHS services as more people require ongoing treatment and monitoring.

While Type 2 diabetes is strongly associated with lifestyle and health inequalities, Type 1 diabetes – which cannot be prevented – continues to affect thousands of younger people across Wales.

Health professionals continue to encourage people to maintain a healthy weight, stay physically active and attend regular health checks to help reduce the risk of developing Type 2 diabetes or identify the condition earlier.