- Primary hyperaldosteronism (PAL) is the main cause for secondary hypertension. PAL also increases the risk for target organ damage. To evaluate the rate of target organ damage in PAL patients versus essential hypertension patients (EHT) and to compare the rate of target organ damage in PAL patients who had adrenal adenoma versus patients with no adrenal adenoma. The study population included patients from the outpatient hypertensive clinic at Soroka University Medical Center between the years 2000-2005. The diagnosis of PAL was performed according to standard protocol. A total of 49 patients were diagnosed with PAL. This group of patients was composed of 12 patients with adrenal adenoma and 37 patients with no adrenal adenoma. The PAL patients were compared to 40 EHT patients. PAL and EHT patients were similar in their age, gender and prevalence of diabetes mellitus. The initial blood pressure measurements were comparable between the two groups. There was significant reduction in blood pressure in PAL and EHT after initiation of appropriate treatment. However, the reduction in systolic blood pressure was higher in the PAL group. Generally, there was tendency for higher rates of target organ damage in the PAL group versus the EHT group. In the PAL patients with adrenal adenoma versus the group with no adrenal adenoma, a significant higher prevalence of brain involvement was observed. The diagnosis of PAL is essential in order to provide the appropriate treatment for blood pressure reduction and prevention of target organ damage.