Introduction Hypertension is a common risk factor for cardiovascular disease. In Sri Lanka, despite the existence of a universal free health system, services are not available for routine screening of hypertension in the general population. This paper aims to describe the epidemiology of hypertension in 35–64 year old residents in Ragama Medical Officer of Health area in the Gampaha district, Sri Lanka.

Methods An age-stratified random sample of 4400 adults between 35 and 64 years of age drawn from the population based electoral list, was invited for a screening programme on cardiovascular risk factors. Socio-demographic and risk factor related data and anthropometric and blood pressure measurements were obtained by trained research assistants. Blood was obtained for relevant biochemical investigations.

Results The prevalence of hypertension (systolic >139 mm Hg and/or diastolic >89 mm Hg) in 2986 subjects (Males 45%), was 30.4% (27.8% in males; 32.5% in females). 31.8% (n=288) were previously undetected. Of the known hypertensives, 19.5% were not on anti-hypertensive medication and only 32.1% were controlled (defined by systolic <140 mm Hg and diastolic <90 mm Hg). Factors associated with hypertension in both males and females were body mass index, waist circumference, fasting blood glucose and serum triglycerides.

Conclusions The prevalence observed is comparable to the prevalences of developed countries with relatively older populations. A considerable proportion of known hypertensives are not on treatment and the observed poor control indicates problems in drug compliance. Interventions targeting lifestyle modification and drug compliance are essential to control adverse outcomes of hypertension.