Most people (90-95%) have essential hypertension. The cause sometimes remains unclear, but may be explained by the interaction of heredity, and/or lifestyle factors. Another 5% have secondary hypertension, which is caused by another medical condition. It is important to diagnose secondary hypertension because sometimes treating the cause can correct the hypertension.
Some medications, such as anti-inflammatories (NSAID’s), steroids, oral contraceptives, or flu medications containing pseudoephedrine, and some natural health food products, such as natural licorice, or ephedra can influence your blood pressure readings. Also alcohol consumption and a number of recreational drugs are known to affect your blood pressure.