Is 121/84 bad blood pressure . female 39 years old?

By the new guidelines, you have borderline hypertension. Either systolic pressure (upper number) above 120 or diastolic pressure (lower number) above 80 is in the borderline category. Combined weight loss and exercise can lower 10% of you blood pressure which will put your numbers in normal range, i.e. 120/80 or less. If you like salty foods like chips, stop them may also normalize your numbers.

Very limited decisions can be made on an isolated blood pressure measurement. Your diastolic or the lower value appears borderline high, systolic is normal. Talk to your doc during your annual visit about it, in case BP remains on the high side, lifestyle changes are to be implemented first, weight loss if applicable.