I am female, 60 years old, normally with low blood pressure around 103/53 heart beat around 50. For the past few years I experienced constant head ache. For the past 6 months I found my blood pressure fluctuates, sometimes reaching 153/77/54. I had a blood pressure monitor on for 24 hours 3 weeks ago and got a n average of 130/80 normal. How come my blood pressure fluctuates daily from 100/49/56 to 155/82/53 as I check my blood pressure at the same Shoppers DrugMart daily.