The blood pressure of the hypertensive persons will be above the normal range and could be greater than 140/90 or equivalent to it. The actual cause of hypertension is not known, yet many factors are said to influence hypertension in human. Some of them are lifestyle aspects, genetic factors, environmental factors, renal and metabolism of the organs and neurohormonal factors. (Porth 2010).The factors that cause primary hypertension are heredity, elevated cholesterol levels, excessive salt intake, obesity, excessive alcohol usage and presence of trace elements such as cadmium or nitrates in the food.(Beevers et al. 2007). The changes in the arterioles results in the increased diastolic blood pressure followed by the increase in the systolic blood pressure, leading to hypertension. If the changes are frequent, then the changes in the hemodynamic mechanism occur. This vascular alteration provides additional blood pressure to the arterioles, thereby raising the diastolic pressure to greater than 90 mm Hg in this case. The peripheral resistance increases because of this increase in the blood pressure. This peripheral resistance is caused by the small arterioles. The small arterioles are made up of smooth muscle cells and these cells contract and relax based on the ion channel transport. The contraction and relaxation is done with the help of the calcium ions. If the ion concentration increases, then the walls gets thickened by the release of the Angiotensin and peripheral resistance occurs. (Cheriyan, McEniery and Wilkinson 2010).
The peripheral resistance will be usually increased with the increase in the pulse rate and ultimately leading to the increase in the diastolic blood pressure and systolic blood pressure. ...
The cardiac output is found to be somewhat greater in the earlier stages and normal at the later stages. The renal blood flow gets decreased with alteration in the renal physiology. The little variations in the blood flow can be easily detected by the muscle part first and there will be response accordingly. The increase or decrease in the blood flow affects the kidney and skin first. The increase in the blood pressure decreases the plasma content of the blood. The increase in the blood pressure creates a lot of stress to the arteries and veins and this creates an abnormal vascular reaction and circulatory homeostasis gets impaired. (Cheriyan, McEniery and Wilkinson 2010). Some of the hypertensinogenic factors that increase the blood pressure are high salt intake, high alcohol intake and obesity. The intermediatary phentoypes are found to be related to hypertension. They are sympathetic nerve activity, rennin Angiotensin aldosterone, sodium excretion, vascular reactivity, cardiac contractility and renin – kallikrein – kinin systems, endothelial derived relaxing factors (EDRF), atrial natriuretic peptide (ANP) and bradykinin, endothelin, Ouabain, etc. - these factors are found to increase the peripheral resistance. (Toda, Ayajiki and Okamura 2007). Blood pressure is found to be associated with the genes, providing necessary evidence for the confirmation of the relationship of genes in hypertension between the parent and sibling. This is further confirmed by the mutagenesis. Mutations in 10 genes have found to decrease the blood pressure. The Angiotensin gene, Angiotensin converting gene, adducin, rennin binding protein, G – protein B3 subunit,