An interaction between pain modulation and arterial pressure control has been proposed on the basis of experimental data in man and animal. Eight hypertensive patients and eight normotensive volunteers were investigated by electrical stimulation of the first trigeminal branch and dental pulp, to evaluate nociceptive sensation and reflex responses. A significant threshold increase of pain sensation and R2, R3 polysynaptic components of the blink reflex, has been found in hypertensive patients.