Essential hypertension

Essential hypertension (hypertension) is a disease of the cardiovascular system, which develops due to primary dysfunction of the vascular regulatory centers and subsequent involment of neurohumoral and kidney mechanisms, characterized by arterial hypertension, functional, and at the expressed stages - by the organic changes of kidneys, heart and central nervous system. The essential hypertension can be diagnosed after exception of symptomatic (secondary) hypertension.

Predisposing factors: genetic factors; disorders of the nervous and endocrine systems, obesity; alcohol; smoking; hypodynamia; elderly age; professional factors: noise and vibration; hormonal factors: increased renin, reduced nitric oxide release.

Etiology

Acute and chronic psychoemotional stress, permanent mental overstrain, hypoxia of brain of any origin, age related neuroendocrine rebuilding (climacterium), salt abuse.

Pathogenesis

Elevation of blood pressure arise due to the imbalance between pressor and depressor factors which lead to development of changes in arterioles and precapillares, changing structure and function of cellular membranes, including smooth muscular cells of arterioles, disorders of activity of sodium-calcium pumps, increasing concentration of the ionized calcium in cytoplasm and finally excessive vascular resistance.

Classification

Classification of hypertension according to blood pressure level

Category	SBP(mmHg)		DBP(mmHg)
Optimal	< 120	and	< 80
Normal BP	120-129	and/or	80-84
High normal	130-139	and/or	85-89
Grade I hypertension	140-159	and/or	90-99
Grade II hypertension	160-179	and/or	100-109
Grade III hypertension	180	and/or	110
Grade IV hypertension	140	and	< 90

Classification of hypertension by extent of organ damage

Stage I	No objective signs of organic changes
Stage II	At least one of the following signs of organ involvement without symptoms or dysfunction: - left ventricular hypertrophy (electrocardiogram, ultrasound); - generalized and focal narrowing of the retinal arteries; - proteinuria and/or slight elevation of plasma creatinine concentration (1,2- 2,0 mg/dl or to 177 mmol/1); - ultrasound or radiological evidence of atherosclerotic plaque (carotid arteries, aorta, iliac and femoral arteries).
Stage III	Both symptoms and signs have appeared as result of organ damage. These include: - heart (myocardial infarction, heart failure); - brain (stroke, transient ischemic attack, encephalopathy, vascular dimension); - optic fundi (retinal hemorrhages and exudates with or without papillodema); - kidney(plasma creatinine concentration more than 2,0 mg/dl or 177 mmol/1); - vessels (dissecting aneurysm, symptomatic arterial occlusive diseases).