My Mom Had A Blood Pressure Of 190 Over 90

my mom had a blood pressure of 190 over 90 and then was prescribed by her doctor medication to help with that this is the first time that she is seeing this doctor and I found it unusual to prescribe someone that medication without having a history of them having high blood pressure my mom says her blood pressure is it normally that high and I wanted to know was it just so high it required
Immediate medication or would observation be the be a more ideal course? The med that was prescribed is NORVASC. Thank you, Diane.