[Hypertension is an independent cardiovascular risk factor and one of the most frequent diseases in Hungary. In the treatment of hypertensive patients usually more than two drugs are needed for the appropriate blood pressure control. Resistant hypertension (RH) is defined when blood pressure remains above target value despite full doses of antihypertensive medications, which consist of at least three different classes of drugs including a diuretic administered in maximal doses. The frequency of RH can reach 20-30% among hypertensive patients. RH increases the cardiovascular risk because of the lack of target blood pressure. RH is multifactorial and it is important to exclude pseudo-resistant hypertension (e.g. poor compliance, white coat effect). In the background of RH we can find lifestyle factors (e.g. obesity, excessive salt intake, alcoholism, etc.) and a variety of drugs (e.g. non-steroids, corticosteroids, sympathomimetics). In the pathogenesis of RH the increased activity of the sympathetic nervous system has an important role. In the treatment of RH we should manage lifestyle factors and it is important to assess the drugs and diseases (e.g. sleep apnea, chronic kidney disease, diabetes mellitus) which may cause increased blood pressure. It is no exact recommendations for the treatment of RH. Therapy often consists of 4-5 various drugs in combination. An important role has the device therapy of RH in recent years (e.g. stimulation of the carotid baroreceptors and renal denervation) as well.]

[In our country as well as around the world the most common chronic disease is the hypertension, and it is also an important risk factor causing disability and premature death. Within this, getting to know the true prevalence of therapy- resistant hypertension is important also from a public health perspective, since the prognosis of it is worse than that of those who reaches goal blood pressure range. It usually comes with hypertension mediated organ damages and higher (2- 2.5 folder) cardiovascular risk. It is prevalence in the literature is from 5% to 30%. The knowledge of the true prevalence depends on many factors, like: there are many different definitions of resistant hypertension, what is the main profile of the data collecting study site and what level of the health care system it works, or for example a questionnaire of a multicenter trial cannot be used totally in each country and study site.]

[INTRODUCTION - The vasomotor centre, the central regulator of the cardiovascular system, is localised in the rostral ventrolateral medulla oblongata. Irritation of this area and/or of the ninth and tenth cranial nerves (that are involved both in the afferent and efferent pathways of the baroreceptor reflex) causes sympathetic hyperactivity, which in some cases leads to severe resistant hypertension. A common underlying cause of this is pulsatile neurovascular compression, a vascular malformation rarely sought for. CASE REPORT - The authors present the case of a middle-aged woman with what had been considered “essential” hypertension. Magnetic resonance angiography showed vascular compression of the medulla oblongata and the departing left ninth and tenth cranial nerves as the cause of her hypertension. CONCLUSIONS - After a literature review the authors draw the attention to this rarely identified cause of resistant hypertension and to the difficulties of its diagnosis.]