How exactly does blood pressure medication work ?

Blood pressure is the force exerted by the flow of blood on the walls of major arterial blood vessels — similar to the flow of water through a garden hose. It is determined by the amount of blood being pumped by the heart in a minute (cardiac output) compared to the resistance of the arterial vessel walls.

This explains why both the amount of fluid in your arteries and the relative elasticity, or “hardening” of the arteries, are factors in high blood pressure. Again, think of a hose. If the water is turned on full blast and there is a kink in the tubing, the pressure builds up. Likewise, the higher the volume of blood and the stiffer the artery, the harder the heart has to work to pump the blood around your system.

Because blood is the foundation of life, nature is mainly concerned with a loss of blood pressure. If your blood pressure drops suddenly, during shock or in reaction to medication for example, our bodies have multiple protective measures to instantly restore homeostasis.

But nature has fewer mechanisms to address high blood pressure, so the best defense is a good offense. How do you know if you have high blood pressure? Up to a third of the people who have it don’t even know it. Since there are virtually no symptoms until hypertension is advanced, the best way to tell is to get regular blood pressure readings

Antihypertensives work in one or more ways: by decreasing blood volume via increased urine production (diuretics); by facilitating blood flow through dilation of blood vessels (alpha-blockers, ACE inhibitors, and sympathetic nerve inhibitors); or by decreasing the rate and/or force of heart contractions, thereby decreasing volume of blood pumped through arteries (alpha-beta blockers, beta-blockers, and calcium channel blockers). Other drugs, like angiotensin blockers and mineralocorticoid receptor antagonists, block natural chemicals produced by the body to combat low blood pressure.