If I have mildly high blood pressure, will aspirin make it worse, and cause severe, short term headache?

I took three aspirins to help with a chronic back pain condition. Soon after I participated in rigorous "exercise" for about ten minutes. Immediately after that my head suddenly felt as though it was going to explode - probably the worst head pain I've had since mild carbon monoxide poisoning in 1979. Fifteen minutes later it faded to a dull ache. This pain enveloped the whole top hemisphere of my cranium. Could aspirin possibly have had anything to do with this episode? Thanks. K.

HBP, according to the books I have read, may be one symptom of high insulin production (hyperinsulinemia) one of the pre-diabetic conditions. Hyperinsulinemia can be responsible for another condition hypoglycemia - low blood sugar. Aspirin interferes with the production of hormones that increase pain, by interfering with the production of some sub-hormones that hypoglycemia can help overproduce. The exercise possibly used up your available sugar in the bloodstream, and the headache may have been your brain trying to tell you it was low on sugar.

www.hufa.org has some basic info on low blood sugar, how to detect it and what to do about it.

Asprin affects people with high blood pressure. I know because my father has it and his doctor told him not to take asprin unless really needed

Acetylsalicylic Acid (ASA) is also known by trade name Aspirin.
It is useful in the relief of headache and muscle and joint aches. Aspirin is also effective in reducing fever, inflammation, and swelling and thus has been used for treatment of rheumatoid arthritis, rheumatic fever, and mild infection. Large doses cause acid-base imbalance and respiratory disturbances and can be fatal, especially in children. I don't know how many pounds of ASA you took but most probably Aspirin won't be the cause of the short term headache.

A small amount of aspirin may actually help reduce high blood pressure. But this means only a quarter to a half a tablet a day. The jury is still out on this but such a small amount will definitely not make it worse and would not cause a headache.
BUT... three aspirins for any reason is way too much and is probably the cause of your headache, especially when followed by rigorous exercise.
So the problem is not the aspirin, just the amount.