Does high blood pressure cause headaches? It may, say British researchers, because blood pressure-lowering drugs seem to prevent them. In a review of 94 studies of people using thiazides, beta blockers, ACE inhibitors or angiotensin II receptor antagonists to treat hypertension, those who took the drugs were less likely to have headaches than those who didn't. And the more patients' blood pressure was lowered, the more likely they were to eradicate their headaches.
Other ways of lowering blood pressure, such as eating a healthy diet and exercising, might have the same effect.