My blood pressure is 165 over 112. i have a headache and i can hear my heart pumping in my right ear. why?

Ordinarily I wouldn't recommend a visit to the emergency room for this BP where prompt care is available, but if this BP is quite a bit higher than your usual baseline BP and you're experiencing a significant headache you'll require prompt medication in order to bring your BP down to about 140/85 as we don't want a too rapid a drop in BP to 120/80. This can wait for a day or so during testing,etc

The most common cause is related to your family tree and your genes and how you feed them. The recommendation is rot always try the DASH diet before meds or at the same time of meds. Most common cause is you are eating more salt that you body can get rid of without increasing your Bp. Google pressure natriuresis curve. And then discuss with your Dr.