HELLO Thanks for writing to us. If I were your treating doctor, I would have taken at least two readings of blood pressure with a gap of 15 days at least. And in beginning high blood pressure can be easily reduced by changing dietary habits and doing exercises. Regarding your query about lisinopril. In my opinion,he is having side effect of lisinopril because it causes hypotension. Please answer my questions so that I can help you better- 1 what s the age of your boyfriend? 2 does his mother or father or grandparents have history of high blood pressure? 3 what s his body mass index(BMI)? 4 Did you do any blood tests, if not I would recommend his doing complete blood count, renal function tests, lipid profile. 5 Is he is taking any other medications except lisinopril? Hope I have answered your query if you have further questions I will be happy to help you. Good luck. Regards Dr Aamir