Can we use this knowledge in treatment of high blood pressure? Why high BP medicines are many a times diuretics?

1. Yes, the knowledge of homoeostasis is used in the treatment of high blood pressure. 

2. Some commonly used theories for treatment of high blood pressure are as follows:

• Angiotensin II receptor blockers (ARBs) are used as medications to treat high blood pressure. These medications block the action of angiotensin II by preventing angiotensin II from binding to angiotensin II receptors on the muscles surrounding blood vessels. As a result, blood vessels enlarge (dilate), and blood pressure is reduced.
• Another method is the use of ‘Angiotensin converting enzyme’ ACE blockers. These inhibitors inhibit activity of ACE and therefore decrease the production of angiotensin II. As a result, these medications cause the blood vessels to enlarge or dilate, and this reduces blood pressure. 

3. Vasodilation reduces arterial pressure. Reduced angiotensin II leads to natriuresis (increased excretion of Na in urine) and diuresis, thereby reducing blood pressure. 

4. Too much salt can cause extra fluid to build up in the blood vessels, raising blood pressure. Diuretics are substances that slow renal absorption of water and thereby cause diuresis (elevated urine flow rate) which in turn reduces blood volume and blood pressure by flushing out salt and extra fluid. Hence, high BP medicines are many a times diuretics.