Over 4 million people aged 40+ in England are estimated to have undiagnosed hypertension after adjusting for differences between clinic and out-of-office blood pressure, a more precise estimate than unadjusted clinic readings (27.7%) give.
The observed prevalence of undiagnosed hypertension among adults aged 40+ in England, based on clinic readings, was 27.7%.
After adjustment with the PROOF-BP algorithm to predict out-of-office blood pressure, the estimated prevalence of undiagnosed hypertension fell to 21.8%.
Predicted prevalence of undiagnosed hypertension was nearly double in males compared with females.
Predicted prevalence of undiagnosed hypertension varied by geographical region in England.
Extrapolated to the national population aged ≥40, approximately 4.2 million people in England are estimated to be unaware of their hypertension.
An estimated 2.9 million or more of those with undiagnosed hypertension could be newly diagnosed through the current diagnostic pathway.
Context: 14.8% of people in England receive treatment for hypertension, but the total number of hypertensive individuals is unclear and can only be estimated statistically.
This study estimated how many people in England aged 40 and over have high blood pressure without knowing it. Blood pressure measured in a clinic or survey visit tends to differ from readings taken at home or over 24 hours, which is how diagnosis is usually confirmed. The researchers used a validated prediction tool (PROOF-BP) with data from the 2017-2019 Health Survey for England to estimate what people's out-of-office readings would likely be. Using raw clinic readings, 27.7% of people without a diagnosis appeared to have hypertension. After adjusting for the likely out-of-office readings, the estimate fell to 21.8%. It was much higher in men (29.8%) than in women (14.6%) and varied across regions, from 16.9% in London to 26.3% in the West Midlands. Scaled to the whole population, about 4.2 million people in England may be unaware they have hypertension, and over 2.9 million of them could be newly diagnosed under the current diagnostic pathway. This research suggests that undiagnosed hypertension is common and that unadjusted clinic readings may overstate it. The estimates could help guide public health efforts to find undiagnosed cases, particularly in groups and regions with higher estimated prevalence. They are statistical estimates and not individual diagnoses.
Castanon A, Hughes A, Grasic K, White M, Sheppard J, McManus R, et al.. (2026). Measurement error adjusted prevalence of undiagnosed hypertension in England: A cross-sectional study.. PloS one. https://doi.org/10.1371/journal.pone.0359861