Can hypertension occur only once? my bp 154/99 indicated stage1 hypertension. hasn't happened again. is it always chronic / can it happen occasionally

Yes: yes you can have intermittent or labile HTN, needs treatment as well.

Yes: Blood pressure is dynamic and fluctuates over 24 hours. It is affected by heart rate, emotions, dietary factors,etc. Physicians never make a judgment on only one bp measurement and prefer one taken after the patient has rested for several minutes in a sitting position. However we are concerned with transient high readings seen in some people and recommend monitoring them and changes in life style

Hypertension is an elevated BP on several visits.