A 32-year-old female presented with symptoms of low energy level, weight gain, cold intolerance, increased bowel movements, flaking, and itchy scalp in the year 2014. On examination, she was found to have a palpable goiter. Her family history was significant for thyroid disease affecting her sibling. Neck ultrasound demonstrated diffusely enlarged thyroid with mild heterogeneous echotexture and left hypoechoic solid nodule measuring 0.75 cm []. Thyroid function test (TFT) was within the normal limits (TSH: 3.4 μIU/mL and FT4: 1.1 ng/dL; normal laboratory values of TSH 0.350–4.940 uIU/mL and FT4: 0.7–1.5 ng/dL respectively) however, antithyroid peroxidase (1446.0 IU/ml; reference range 0.0–5.6 IU/ml) and Tg antibodies (95.4 IU/ml; reference range 0.0–4.1 IU/ml) were high. A diagnosis of euthyroid Hashimoto's disease was made, and the patient was followed up on ultrasound and TFT.\nIn the year 2016, the patient presented with irritability and anxiety. Repeat ultrasound showed status quo. However, there was a surge in thyroid antibodies and an increase in TSH levels (7.2 μIU/mL). The clinical impression was consistent with Hashimoto's thyroiditis and the patient was started on low-dose thyroxine, which she tolerated well for 3 years. On yearly follow-up, there was a downtrend in thyroid antibodies, TSH returned to normal range, and findings on ultrasound remained stable.\nIn October 2019, the patient presented with syncopal episode. Evaluation of TFT demonstrated low TSH of 0.003 μIU/mL and raised FT4 of 2.4 ng/dL. The patient was asked to stop thyroxine tablets and to repeat TFTs in 4 weeks. Repeat TSH was <0.002 μIU/mL and FT4 of 2.6 ng/dL. I-123 thyroid uptake and the scan was performed, which demonstrated findings consistent with Graves' disease [] with 24 h uptake of 63.6% (normal range 10%–25%). The patient was subsequently treated with 15.9 mCi of radioiodine (I-131). Follow-up in 6 weeks of radioiodine therapy, the patient was clinically stable.
A 43 year old obese female, married, mother of 4 children was diagnosed as having hypothyroidism in the beginning of year 2011 when she felt lethargic and her TSH level was raised to 72 uIU/ml. She was started on thyroxine 150 mcg/day which was later on decreased to 100 mcg when her TSH level was suppressed to 0.5 uIU/ml after 1 month. After further 4 weeks her serum TSH came out to be further suppressed at <0.005 uIU/ml so thyroxine was stopped. The patient came for follow up after 8 weeks with serum TSH of 0.2 uIU/ml and T4 of 16.20 ng/dl (4.5-11.3). She then lost to follow up and returned in September 2011 with Thyroid function test showing serum TSH of <0.005 uIU/ml and FT4: 2.36 ng/dl. Thyroid antibodies were strongly positive. At this time she also had complained of palpitations, increased appetite, increased bowel movements, decreased sleep and tremors of hands. On examination she had no goiter and eye signs but had fine tremors of hands. She was advised to start carbimazole.