Given the popularity of Viagra to treat erectile dysfunction in men, it is no wonder that so many anxious males have questions regarding how the drug works and what are the possible side effects. Viagra has been available since 1998 and is FDA-approved. It has a long proven safety record with few side effects reported in clinical trials. The obvious main reason to take the small blue pills is to help obtain and sustain an erection during sexual intercourse. However, some men also choose to take Viagra to lower their blood pressure. The drug increases the amount of nitric oxide in your system, which then lowers your blood pressure. This is especially true if you take other similar drugs such as nitrates that work in much the same way as Viagra. However, if you plan to take Viagra specifically to lower your blood pressure, you should discuss your current health condition with your doctor beforehand. Certain diseases and medications can cause problems when combined with Viagra.