Hypertension is among the leading causes of death in Tanzania, and also it is a public health rattrap. This affecting most people in Tanzania, whereby life modification factors are less considered. It is a common non-communicable disease which may lead to cardiovascular diseases, heart failure and sometimes sexual dysfunction. 
In 2010, the global burden of hypertension was estimated at ~ 1.4 billion, and is likely estimated to exceed 1.6 billion by 2025. In 2016, non-communicable diseases accounted for 40.5 million or 71% of deaths globally; 17.9 million (44%) of non-communicable disease related deaths were due to cardiovascular disease with hypertension as the leading risk factor.
According to WHO 2013, explained controlled hypertension as average systolic blood pressure < 140 mmHg and an average diastolic blood pressure of < 90 mmHg. All these factors based on both risk factor approach and cardiovascular approach. [2, 3]
Studies done in sub-Sahara Africa (SSA) indicate that hypertension is a widespread problem, and it has been reported to be as high as 38% in some communities. It is estimated that out of the approximately 650 million people in SSA, between 10 to 20 million may have hypertension however many countries in SSA still lack detailed information on the prevalence of hypertension. Hypertension is a growing public health problem in sub-Saharan Africa.
The highest prevalence of uncontrolled hypertension is reported in sub-Saharan Africa, and treatment for hypertension is unacceptably low. Uncontrolled hypertension (UHTN) in SSA is a challenge despite increasing knowledge of hypertension care and the availability of low-cost medications. A 2013 systematic review showed a very low level of treatment (18%) and a high (97%) prevalence of uncontrolled hypertension in SSA . Morbidities, such as stroke, associated with uncontrolled hypertension are costly to treat and pose a burden to health care systems in SSA that are already weak. High uncontrolled rates of hypertension have economic and public health implications .
Among patients who have detected HTN, few are taking treatment and, among those on treatment, very few are controlled . Untreated or uncontrolled, hypertension is the single largest contributor to cardiovascular disease globally, causing stroke, heart failure, coronary artery disease, and kidney disease, and also is a major contributor to kidney disease .
Hypertension is often called ‘the silent killer’ because it is a disease that shows no early symptoms, and simultaneously, is the single most significant risk factor for heart disease, The complications of hypertension are related either to sustained elevations of blood pressure, with consequent changes in the blood vessels and heart, or to the accompanying atherosclerosis that is accelerated by long-standing hypertension.
Hypertension burden is increasing in East Africa, local studies done in 2017 have shown an extensive evidence of growing burden of hypertension in Tanzania with variation in prevalence, there is extensive evidence of the growing burden of chronic diseases in both rural and urban populations of Tanzania. Between 1990 and 2000, the prevalence of hypertension ranged from 3–27% in rural and 5–39% in urban. Between 2000 and 2016, hypertension prevalence ranged between 13–70% in rural and 12–65% in urban .
A study done in states that hypertension in sub-Saharan Africa is a widespread problem of immense economic importance because of its high prevalence in urban areas, its frequent under diagnosis, and the severity of its complications . In Tanzania for example, a study done in Northern Tanzania in 2019 showed the complications such as heart failure, stroke, renal failure, ischemic heart disease, chronic kidney disease .
Several factors related to poor control include ageing, obesity, lack of exercise, gender, race, access to health care, drug adherence and co-morbid conditions such as diabetes. Results from studies suggest that it may be possible to solve this public health problem. This requires interdisciplinary approaches to increase patient awareness and physician adherence to guidelines to realize the full benefits of hypertension research . Controlled hypertension is key to prevent hypertension related complications such as stroke, chronic kidney disease and heart failure.
In a study done involving six countries in Sub-Saharan Africa around 2018, showed that between 44–93% of hypertensive patients were unaware of their disease, only 18% were on medication, and a mere 7% achieved adequate blood pressure control overall . Also, in study done at Mafia Island in Tanzania around year 2016, out of the 118 participants who were aware of having hypertension, 68 (57.6%) were currently taking medication. From those taking medication, only 14 (20.6%) had controlled hypertension. Therefore aim of this study was to determine the prevalence of controlled systemic hypertension and its associated risk factors among hypertensive patient attending clinic at Mbeya Zonal Referral Hospital, Tanzania.