A questionnaire-based survey of 1843 patients with hypertension was conducted in Denmark to profile patients' experiences of antihypertensive therapy. A high proportion of patients were found to have experienced adverse effects attributable to antihypertensive drug therapy. The pattern of adverse event reporting was consistent with the known pharmacology of the drugs prescribed. Thus, cold extremities were reported most often with beta-blockers and peripheral oedema was associated with calcium channel blockers. Patients' experiences with losartan indicated that this drug was tolerated better than other types of medication, but this finding was based on a relatively small dataset. It is concluded that adverse experiences attributable to antihypertensive medications may be a significant obstacle to the implementation of effective treatment of hypertension and that greater physician awareness of the problems patients experience may help provide hypertension therapy that is well tolerated as well as effective.