Jaap Deinum's research is in the field of clinical hypertension. This relates to his training as an internist with a focus on hypertension, as well as to his PhD thesis (1999) on the structure and regulation of prorenin, a blood pressure prohormone at Erasmus University Rotterdam. He is currently involved in clinical research, mainly on secondary hypertension, with emphasis on adrenal causes within the setting of the Radboud Adrenal Center. He is running a multicenter diagnostic trial on primary aldosteronism with randomized arms and clinical outcome as endpoint and initiated a recently started prevalence study of primary aldosteronism in newly diagnosed hypertensive patients in general practice. He is also involved in translational projects from bedside to bench on hypertension and adrenal and renal pathophysiology. He is fascinated by integration of compassionate care, science and rational parsimony and is open to collaboration in this field.