The Japanese Society of Internal Medicine Acta Medica Okayama 0918-2918 59 15 2020 Coronary Spastic Angina Induced by Adrenal Insufficiency 1873 1877 EN Yuki Otsuka Department of General Medicine, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences Ko Harada Department of General Medicine, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences Miho Yasuda Department of General Medicine, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences Yasuhiro Nakano Department of General Medicine, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences Kou Hasegawa Department of General Medicine, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences Fumio Otsuka Department of General Medicine, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences Adrenal insufficiency patients are treated with glucocorticoid replacement therapy. However, mimicking the in vivo circadian rhythm of cortisol levels is challenging, and suboptimal replacement increases the risk of mortality from cardiovascular disease. We herein report a case of coronary spastic angina (CSA) with simultaneous low early-morning serum cortisol levels in a patient undergoing corticosteroid replacement therapy for primary adrenal insufficiency. Steroid therapy is reportedly effective for refractory angina, but underlying adrenal deficiency has never been revealed. Our case intimates the probable risk of CSA as a complication of relative adrenal insufficiency and highlights the effectiveness of dexamethasone in these patients. No potential conflict of interest relevant to this article was reported.