Abstract: This paper presents a tortuous diagnostic and treatment process of a young patient with hypertension complicated by hypokalemia, early-onset cerebrovascular disease, and adrenal nodules, and systematically analyzes the clinical reasoning pathway of primary aldosteronism (PA). The patient was a 31-year-old male with a history of hypertension for over 10 years complicated by right basal ganglia hemorrhage. During multiple medical visits, he was also found to have hypokalemia and a right adrenal nodule. However, across four separate hospital admissions, he was consistently diagnosed with primary hypertension. Based on the typical clinical manifestations, a general practitioner considered PA. However, aldosterone/renin ratio tests were negative three times before showing a positive result on the fourth attempt. Subsequently, PA was confirmed by a seated saline infusion test and a captopril test. Finally, ⁶⁸Ga-Pentixafor C-X-C chemokine receptor type 4 (CXCR4) positron emission tomography (PET)/CT and adrenal vein sampling (AVS) were performed to locate the lesion, confirming a right aldosterone-producing adenoma. The patient eventually underwent laparoscopic right adrenalectomy, after which blood pressure was decreased, serum potassium returned to normal, and antihypertensive medications were discontinued. This case emphasizes the importance of clinical reasoning in the diagnosis of PA, highlighting the need for clinicians to improve their understanding of PA, emphasize the evaluation of first-hand data, comprehensively analyze the reliability of laboratory results, and adhere to patient-centered principles. The diagnostic and treatment process of this case fully embodies the problem-oriented, evidence-based clinical reasoning "5A procedure," providing a concrete example for cultivating clinical thinking in young physicians.