Half of all adults are at risk of developing high blood pressure, but many are not aware, a survey suggests.
16m people in the UK have high blood pressure
Some 397 (24%) of the 1,675 people surveyed by UK chain Moss Pharmacy had high blood pressure, putting them at risk of heart disease and strokes.
Another quarter were identified as being at risk because of previous medical history or lifestyle.
Moss Pharmacy said people unaware they were at risk may add to the danger by making bad health or lifestyle choices.
The results will be unveiled on Monday at the Royal Pharmaceutical Society's conference in Manchester.
Smoking, previous strokes and diabetes can put you at risk of high blood pressure.
At least 10 million people have high blood pressure in the UK but Chris Street, the health and pharmacy adviser at Moss, which has 800 outlets across the country, said much of the population remained unaware of their condition.
"Many people, especially the younger population, are totally unaware that they either actually have high blood pressure or have a combination of factors that place them at serious risk of developing heart disease.
"They, therefore, may make health and lifestyle choice that are adding to their risk.
"People simply can't afford to gamble with their health.
"Anyone who suspects they are at risk from high blood pressure should seek advice from their pharmacist or GP."
A Blood Pressure Association spokeswoman agreed.
"I think more and more people are becoming aware of high blood pressure.
"But too many people still do not know what to do about it."
But a separate study by the University of Bradford and a GP practice in Frimley, Surrey, has offered hope to people at risk of high blood pressure.
A total of 33 patients people with high blood pressure were put on two different courses of treatment and the results were compared.
One group underwent the standard care, which involved seeing a GP and being prescribed a course of tablets, and then went on to receive a tailored-medicine plan from a pharmacist, which involved regular check-ups, as well as keeping in contact with the GP.
The second group did it in the reverse order.
The results showed that blood pressure was reduced to the target level for 30 patients during the tailored treatment, compared with 16 receiving the usual care.
Lisa Jamieson, the pharmacist involved in the study, told BBC News Online she believed the model piloted could work elsewhere.
"It worked really well, at first the people were sceptical about why they weren't seeing a doctor but they soon accepted it and the results speak for themselves."