Your doctor has to consider your co-existing condition(s) and other factors when deciding what medication to prescribe.
Diastolic pressure reflects the lowest pressure to which our arteries are exposed. In younger people (such as yourself), the higher the diastolic, the greater the risk for adverse events. In people over fifty, systolic hypertension poses a much greater risk. In people over sixty, it is the pulse pressure - the difference between systolic and diastolic pressures- not the numbers themselves- that is very important. The higher the difference, the higher a chance of an adverse event. Generally, diastolic blood pressure decreases with age.
The elevations in diastolic pressure are thought to be caused by combined changes in our blood vessels and the heart. A desirable level of diastolic pressure is 75 mmHg. Readings above this level are associated with an increase in adverse events. EVERY 10mmHg increase in diastolic blood pressure over 75mmHg doubles the chances of adverse events.
Interestingly, for systolic blood pressure the incidence of adverse events such as a heart attack, stroke or kidney failure doubles with every 20mmHg increase.
The drugs that are recommended to treat diastolic hypertension in some people (depending on co-existing conditions etc.) are ACE inhibitors and calcium channel blockers. The diuretics and non-selective beta blockers would not be first choices in therapy.
I hope you can bring that diastolic down. Good to hear your labs are OK!!!