In people older than 50, the main abnormality is high systolic blood pressure, often associated with low diastolic pressure.
After midlife, the diastolic blood pressure often falls.
The change in blood pressure as you age is caused by progressive stiffening of the aorta and its main branches.
As the aorta stiffens with age, it expands less when blood from the heart enters it, causing higher systolic blood pressure. Also because of the stiffening, more of the blood in the aorta and its main branches is forced into other smaller blood vessels when the heart beats, thus, less is present between heartbeats to support the diastolic blood pressure, which becomes lower.

Does this person have a history of hypertension?
Does it take antihypertensive drugs?