Main study parameters/endpoints: The quantity of antihypertensive drugs patients are using to obtain target blood pressure, expressed in Daily Defined Dosages, is used as the main study parameter. There is no criterion standard for accuracy of the diagnosis of PA-subtype, but we assume that if treatment is based on a more accurate diagnosis, treatment is more effective. The most important secondary endpoints are the costs of the diagnostic course and long-term medical treatment and the quality of life as assessed by a validated questionnaire.