Question: I am a 58 year old woman who was diagnosed with thyroid cancer four years ago. I had surgery to remove a very small tumor and then had obliteration therapy with the smallest dose of radioactive iodine that is used for treatment.

I take 0.135 mg of Synthroid each day and mythyroid and calcium numbers look good, but I am still tired and have a lot of muscle pain. What else do you think I should take to substitute the hormones, etc. that I can no longer make?

Dr. Hibberd's Answer:

Thyroid cancer is often cured by thyroidectomy and a single oral radioactive iodine drink following surgery. Over-suppression of any remaining thyroid tissue is achieved with a single daily dose of thyroid hormone by mouth.

Persistent muscle aches and fatigue should be further evaluated by review of your thyroid hormone (T3 and T4) levels. Since both over-and under-supplementation of thyroid hormone may produce these symptoms, it makes sense to start here.

Be sure the evaluation of your muscle pain and fatigue evaluation includes the consideration that your parathyroid glands may have been inadvertently injured or removed during your thyroid surgery. Treatment consists of calcium and vitamin D supplementation.

It would be prudent to have your calcium and phosphorus levels reviewed. A deficiency of parathyroid hormone will usually produce low calcium levels and elevated phosphorus levels. The symptoms of deficiency include fatigue and muscle aches and can cause serious heart rhythm disorders and heart failure.

Should the source of your problems remain unclear, your doctor has very clear methods for further evaluation of fatigue and muscle discomfort in survivors of thyroid malignancy.

Let me know how this helps you. Thank you for allowing me to comment on an often overlooked problem in post-operative thyroidectomy patients.