Yes My Dr Just Throwed Me On Lisinopril HDTV 20

Yes my dr just throwed me on lisinopril HDTV 20 12.5 mg I had my yearly check up my blood pressure was good on top but 98 on the bottom so he wants me to try this med I don't know it's a water pill I'm I holding fluid somewhere that I don't know of ? Jennipher