Taking a few moments to concentrate on breathing deeply can be a great help. Meditation and yoga are other great activities to reduce stress. We recommend Yoga Burn, by Zoe Bray Cotton for an amazing at-home yoga workout.  In the long term, creating a routine that including one or more of these stress reduction techniques will be important to keep your blood pressure down in normal levels. [2]
In Sweden, blood pressure is often wrongly measured at clinics with the subjects lying down. The differences tend to be small, however: when seated, the systolic blood pressure registers a little lower, and the diastolic a little higher. Trying this on myself, I noted readings of 116/73 averaged over several seated measurements and an average of 119/72 lying down.

If you injure yourself right at the start, you are less likely to keep going. Focus on doing something that gets your heart rate up to a moderate level. If you're physically active regularly for longer periods or at greater intensity, you're likely to benefit more. But don't overdo it. Too much exercise can give you sore muscles and increase the risk of injury.

Elevated blood pressure refers to an increase in the pressure or tension applied to blood vessels. Blood pressure is measured by providing two different readings, including systolic blood pressure and diastolic pressure. Blood pressure levels that raise beyond 120/80 is considered elevated. At 130/80, a person is considered to be experiencing high blood pressure. High blood pressure is often classified into two stages. State 1 hypertension is diagnosed when blood pressure levels fall between 130-139/80-89. Stage 2 hypertension is diagnosed when a patient’s blood pressure becomes higher than 140/90.
Exercise can also lead to lower blood pressure. Although performing moderate to vigorous exercise leads to higher blood pressure during activity, it is lowered afterwards. A wealth of studies indicate that getting 150 minutes per week of exercise—whether walking, cycling, gardening, dancing, or weights—can lead to significant drops in blood pressure over time. Try to exercise every day, but even three or four times per week can bring on big improvements.