Can symptoms of hyperthyroidism occur when someone is on thyroxine supplements?

Question

Hello doctor,

I have symptoms like severe hair fall, swelling in my throat, a shaky feeling in my thyroid, blurred eyes, and mood swings. Also, the tablet Thyroxine has stopped making me feel better. However, I cannot sleep without taking a dose. The symptoms have worsened in the last one to two years. My TSH levels have changed drastically from 69 mIU/mL to 0.2 mIU/mL. Currently, my T3 and T4 levels are normal. T3 is 6.9 ug/dL and T4 is 22 ug/dL. I am on tablet thyroxine 175 mg. I was diagnosed with Hashimoto's disease as well. I have symptoms of both hyperthyroidism and hypothyroidism despite having standard T3 and T4 levels. I was diagnosed with thyroid problems at the age of seven. I had goiter and autoantibodies. This year my thyroid levels have changed drastically. My TSH levels went from 69 mIU/mL to 13 mIU/mL to 02. mIU/mL. Also, my autoantibodies went from 255 mIU/mL to 8 mIU/mL. Do I have the grave's disease, or are the symptoms due to goiter?

Kindly advise.

Answer 1

Hello,

Welcome to icliniq.com.

I understand your concern.

T4 (Thyroxine) value of 22 ug/dL is high, and TSH (thyroid-stimulating hormone) of 0.2 mIU/mL is below normal. I suggest you decrease the dose of tablet Thyroxine to 150 mcg daily and recheck TSH and free T4 after six weeks. Your symptoms could be due to over replacement of Thyroxine. Changing from hypothyroidism to hyperthyroidism is uncommon, but first, I suggest decreasing the dose of Levothyroxine to 150 mcg and maybe eventually down to 125 mcg daily. Do you have any weight changes? Are your bowel movements regular? Are you on any medications? Do you have a regular menstrual cycle? It would help if you also got your iron and vitamin D levels checked.

I hope this helps.

Kindly revert in case of further questions.

Thank you.