Most individuals have never heard about this particular hormone, yet it plays an important role in cardiovascular health. Aldosterone is produced in the cortex of the adrenal glands, which are located above the kidneys. Understanding this hormone will help you understand your body better, and help you take measures to ensure optimal health. Aldosterone affects the body's ability to regulate blood pressure. It sends the signal to organs, like the kidney and colon, that can increase the amount of sodium the body sends into the bloodstream or the amount of potassium released in the urine. The hormone also causes the bloodstream to re-absorb water with the sodium to increase blood volume. All of these actions are integral to increasing and lowering blood vessels. Indirectly, the hormone also helps maintain the blood's pH and electrolyte levels. Aldosterone is closely linked to two other hormones: renin and angiotensin, which create the renin-angiotensin-aldosterone system. This system is activated when the body experiences a decrease in blood flow to the kidneys, such as after a drop in blood pressure, or a significant drop in blood volume after a hemorrhage or serious injury. Renin is responsible for the production of angiotensin, which then causes the release of aldosterone. Once the body is rehydrated and has proper salt levels in the blood, renin levels fall, and aldosterone levels lower as a result.