The Thyroid Swing: A Patient's Journey From Hypothyroidism to Hyperthyroidism

Abstract

The flip from hyperthyroidism (HT), as observed in Graves' disease (GD) cases, to hypothyroidism associated with Hashimoto's disease (HD) has been widely recognized and documented. However, the converse is infrequently observed. The observed phenomenon is likely attributed to the major role played by thyroid-stimulating hormone receptor antibodies (TRAbs) in this alternating disease pattern and a substantial reduction in thyroid tissue mass that could be stimulated by these antibodies. Therefore, here we present a case of one middle-aged individual experiencing this transitional switch from hypothyroidism to GD. A 42-year-old male patient diagnosed with HD-related hypothyroidism for two years has remained stable with levothyroxine medication since diagnosis. However, his symptoms of thyrotoxicosis, such as anxiety, weight loss, and palpitations, had appeared during his follow-up time at the clinic. Physical examination revealed mild exophthalmos, which confirmed HT by thyroid function test results. The possibility of levothyroxine-induced HT was initially considered, although the observed symptoms failed to ameliorate despite the reduction and discontinuation of levothyroxine. The diagnosis of GD was confirmed after subsequent examination, and a follow-up was carried out. This particular case study underscores a distinctive correlation that carries substantial implications for the diagnosis and treatment of GD. The consideration of this shift is warranted in cases where HT continues to exist despite the reduction or cessation of levothyroxine treatment. The diagnosis is established through antibody titers and a radioiodine uptake scan. Treatment choice is based on the illness's stage and the patient's and care provider's preferences. In the initial phase, anti-thyroid medications may be employed. It is imperative to conduct regular follow-ups on these patients due to the potential transient nature of this clinical condition.