Thyroid scan/uptake shows mild hyperthyroidism, blood-work shows hypothyroidism. What's up with that?

Labs are right. Thyroid scan/uptake shows how active someone's thyroid is in trapping iodine, but not whether or not their thyroid is able to convert iodide to iodine and make thyroid hormone with it. In this situation, the labs tell the true story - that the thyroid can't make enough thyroid hormone. Uptakes and scans are morehelpful in people with hyperthyroidism, and don't add much info in hypothyroidism.
Thyroiid scan unhelp. Thryroid scans do not help with hormonal status of the gland.

Related Questions

My thyroid scan/uptake shows mild hyperthyroidism, but blood-work shows hypothyroidism. Does this happen often? What should I do?

Reverse T3 (liothyronine) Thyroid scan/uptake shows mild hyperthyroidism, but blood-work shows hypothyroidism. Thyroid gland is working hard but producing ineffective hormone. Test for reverse t3 (liothyronine). Thyroid hormone replacement is reasonable. Possible mutations in the sbp2 gene: abnormal thyroid function tests, low triiodothyronine (t3 (liothyronine)), high thyroxine (t4) and reverse t3 (liothyronine), and slightly elevated thyrotropin.
Antibodies. You probably have several types of thyroid antibodies floating around your system. Some cause hyperthyroidism while others may block their effect on the thyroid receptor. Treat your levels- if you're hypo - treat with synthroid (thyroxine). Monitor function and antibody levels over time.