I don't have high blood pressure, but was bordering. And my friend was bordering.
If your parents had high blood pressure, you probably just got unlucky. Genetic hypertension is hard to avoid.
Excess weight, sodium sensitivity, lack of exercise, lack of sleep, stress, etc. can all raise your blood pressure.
Talk to your doctor before you do anything, but I'd suggest taking garlic pills, eating oatmeal once a day, 30 minutes of daily exercise, getting sleep and finding a happy hobby to help you unwind.
Both my friend and I got ourselves into normal ranges by doing this.
What I do know is that my father does get stressed really easy. I feel I am the same with work and stuff. Other than that I don't know what could be at fault. I have a healthy lifestyle. My cardiologist says that my nasal septum isn't straight and I do not get enough oxygen making my heart work harder. He has put me on Norvasc 5mg until I have the surgery.