A new study has found that only half of people in England who are being treated by a general practitioner (GP) for high blood pressure have it properly controlled. Additionally, millions more are unaware they have the condition. The research, conducted by Oxford University and published in the BMJ Public Health journal, highlights that 59% of people with hypertension—also known as high blood pressure—are undiagnosed, putting them at greater risk of serious health issues like strokes, heart attacks, and early death. The study analyzed data from 1.4 million adults participating in the Our Future Health program between 2022 and 2025. It found that over a third of adults (37%) had high blood pressure, defined as a blood pressure reading of 140/90 mmHg or higher. Of those, six in 10 were unaware they had the condition. Hypertension was also more common in men than in women, with 42% of men affected compared to 29% of women across all ages. Older adults were also more likely to have high blood pressure. Despite improvements in detecting and treating high blood pressure during the 2000s, the study found that progress has stalled since around 2011. There are also signs of worsening trends since the start of the Covid-19 pandemic, possibly due to disruptions in healthcare services. Wenyu Liu, a medical statistician at Oxford Population Health and lead author of the study, said the current approach to detecting and treating high blood pressure is "not fit for purpose." The researchers emphasized that the high number of undiagnosed cases was the most striking finding, and only half of those being treated by a GP had their blood pressure under control. Dr. Iain Turnbull, a GP and clinical research fellow at Oxford Population Health, noted that it is unclear why half of the patients taking blood pressure-lowering drugs still have uncontrolled hypertension. Possible reasons include individual variations in blood pressure, the need for dose adjustments or multiple medications, and other health conditions. Practical and social factors, such as side effects, treatment routines, and lifestyle choices, may also play a role. The study did not have access to prescribing records, and a single blood pressure reading may not reflect a person's usual levels. Prof. Bryan Williams, chief scientific and medical officer at the British Heart Foundation, said the study "paints a concerning picture" of the scale of undiagnosed high blood pressure in the UK and the challenges of keeping it under control in those already receiving treatment. He stressed the need to rethink how hypertension is identified, treated, and managed to help prevent heart attacks and strokes that could otherwise be avoided.