Post extraction bleeding may happen due to few reasons like excessive spitting, drinking by straw, touching the wound with tongue or finger, unusual placement of gauze piece etc.
But as you are having hypertension , medicines for blood pressure usually contains Alpha-Blockers which makes blood to flow easily. But one question arise , did you follow the instructions given by your dentist?
Do not spit unnecessarily as it will create force and your socket will not heal. Do not eat hard and hot food or any hot liquid. Eat some ice cream . Have semi liquid diet for about a day or two.
Bleeding will surely surrender.
Take Tab. Dentaforce DT 10mg twice a day .
Next Steps
Consult your Dentist who treated you