Why is my blood pressure fluctuating wildly?

It depends. It is normal for ones blood pressure to vary from moment to moment. Check your pressure each morning, sitting and standing, for 1 or 2 weeks. The major determinant of a significant change usually is the amount of salt one ingests (for example, the day after a salty meal, one expects a significant rise in blood pressure). If ones pressure is consistently greater than 125 systolic, see your dr.