A case of thyroid storm caused by Graves' disease misdiagnosed as panic attack due to panic disorder

Abstract Background Graves' disease is characterized by hyperthyroidism and the symptoms of Graves' disease often overlap with those of panic disorder, which may make it difficult to distinguish between the two conditions.In this report, we describe how proper diagnosis of thyroid disease in patients with mental illness can lead to appropriate treatment.Case presentation We encountered a 34-year-old woman in whom thyroid crisis from Graves’ disease was misdiagnosed as panic attack. The patient was being managed as a case of panic disorder and bipolar disorder in a psychiatric outpatient setting. About 6 months before presentation, she had lost about 16 kg in weight, and a month before presentation, she developed several unpleasant symptoms as her condition worsened. Several weeks before, she had severe palpitations, tachycardia, and discomfort in her throat. She became unable to eat solids and ate only yogurt and gelatin and felt difficult to take psychiatric drugs.A day on the Sunday morning, she visited our department of emergency outpatient with severe nausea. Examination revealed proptosis, and so thyroid function tests were requested in addition to routine blood tests. There was no improvement in her condition, and she returned to hospital in the early hours of the next morning. Based on her symptoms, she was diagnosed as having panic attacks due to panic disorder and was given diazepam injection and allowed to go home. There was no suspicion of Graves' disease.Later that day, the thyroid function test results became available and thyroid storm was suspected. The endocrinology department was consulted immediately and she was referred and hospitalized the next day. During hospitalization, she was treated with steroid and radioisotope therapy, and was discharged from hospital in three weeks. Conclusion Psychiatrists and doctors engaged in psychosomatic medicine need to consider the possibility of thyroid disease as a differential diagnosis of panic disorder. It is necessary to check thyroid function at the initial examination when a patient presents with symptoms of severe panic attack.