Blood Pressure

Blood Pressure is the pressure or force of blood provided against the blood vessel wall. When the heart contracts, it forces the blood out of the left ventricle. Upon exclusion, it travels through blood vessels to different body parts. While moving, it exerts a force on the blood vessel. Due to friction of blood with the blood vessel, pressure arises that is called blood pressure. Most of the blood is forcefully released from the heart when the heart contracts. This contraction is called systole, and the pressure generated in the vessel is called systolic blood pressure; when the heart gets relaxed and filled with blood, the pressure level at the vessel reaches a minimum, called relaxed or diastolic blood pressure. The optimal blood pressure is less than 120/80 (systolic/diastolic).

In the body, blood pressure is regulated via a complex regulatory process that involves numerous pathways, including the renin-angiotensin-aldosterone system, endothelins, mineralocorticoid, arterial baroreceptors, atrial natriuretic peptide, and glucocorticoid steroids dependent mechanisms. Any dysregulation of these can lead to the development of hyper- or hypotension. Hypertension is when either systolic or diastolic or blood pressure is raised and maintained consistently to more than normal levels. Increased systemic vascular resistance, increased cardiac output, or both are responsible for this adverse situation. An unhealthy lifestyle, irregular physical activity, aging, and certain health conditions, such as obesity and diabetes, can make blood vessels less elastic, increase systemic vascular resistance, and reduce vasodilatation, causing higher systolic blood pressure (frequently with a normal diastolic pressure). This can critically harm vital organs like the kidneys, heart, brain, eyes, and other body organs. In contrast, hypotension develops when blood pressure fails to maintain the minimum level. The most prominent reasons for hypotension could be pregnancy, impaired heart and heart valve conditions, endocrine disorders, dehydration, blood loss, septicemia, anaphylaxis, etc. Because of a lack of blood, oxygen, and other nutrients, a hypotensive person feels tired or dizzy. Several medications are now used to control abnormal blood pressure. For example, angiotensin-2 receptor blockers (ARBs), angiotensin-converting enzyme (ACE) inhibitors, calcium channel blockers, diuretics, and beta channel blockers are mostly prescribed by physicians to treat abnormal blood pressure. [MM Towhidul Islam]

See also blood, blood thinner.