Hello,
Diastolic blood pressure in the range of 70-90 is considered normal.
Single reading of diastolic blood pressure above 90 is definitely normal. It may be due to some acute stress, exercise, physical activity, etc.
Single reading of blood pressure above is not sufficient to call it hypertension. Please follow my advice given below.
Thank you.
Next Steps
Please take sequential 3 readings with 5 minutes interval on 2 separate days in a week.
After this consult me back.