Hypertension history. headaches since mon w/pn & press throbbing w/pulse. ha wed worst of life, splitting head, light/sound sensitive, nauseated, threw up 5x. could dehydration or acute htn be cause?

This is an emergency: Honestly, worst headache of life, that seems to be 10/10 in pain, could be a life-threatening headache. Things that are are life threatening: intracranial bleed and hypertensive emergency. Other causes may be migraine, dehydration, etc., but I would not risk it. I think the best thing to do is go to the ER, get your BP checked, and possibly a CT.

Hypertension: In your age group, I am a big fan of being aggressive in looking for a cause. Especially looking for fixable cause such as fibromuscular dysplasia. But the headache is troubling. And I would go to your local emergency room for a CT of the head. The "worst headache of my life " is of concern for trouble in the head. Then sit down and discuss these symptoms with your doctor .