Blood pressure increase with age because the arteries loose elasticity. This is called secondary hypertension. In the other 90 percent of patients, the cause is unknown and is referred to essential hypertension. How to Decrease Blood Pressure There are many ways to decrease blood pressure. Blood pressure can be decreased if a person exercises, doesn't smoke, limits salt intake, limits alcohol intake and if obese, looses weight.
Blood pressure is regulated largely by the nervous system.
Hemoglobin , the iron-protein compound that gives blood its red color, also plays a role in regulating blood pressure. However, hemoblobin's affect is usually localized and is not very useful when trying to control blood pressure on a large scale. Hemoglobin contains nitric oxide, a gas that relaxes the blood vessel walls, thus increasing blood flow. It controls the expansion and contraction of blood vessels, and thus blood pressure, by regulating the amount of nitric oxide to which the vessels are exposed. Individuals with high blood pressure can be given medication to lower their blood pressure.