Is lower back and tailbone pain caused by my hypothyroidism?

No: should not be caused by your thyroid.

Not necessarily...: Hypothyroidism might cause symptoms of muscle pain and muscle weakness which could happen more often in a generalized type of fashion. It is not common that it causes very localized pain although it cannot be disregarded depending on the person. Weight gain as a result of thyroid issue can cause low back pain. In this case I would also get evaluated for other possible reasons.

No: Hi. No, your low back & tailbone pain would not be a consequence of your hypothyroidism. In fact, assuming your hypothyroidism is treated with the right dose of thyroid hormone replacement and your thyroid function tests are normal, your symptoms from hypothyroidism will all have resolved. It is only untreated hypothyroidism that has hypothyroid symptoms.

Spine Pain Options: This pain in the distribution as you suggested is the result of an irritated nerve or facet joints or other injury typically in the lumbar spine (low back) which are caused by herniated disks, spinal stenosis or degenerative disc disease, etc requiring further evaluation by a spine specialist and may be candidate for facet injections/radiofrequency ablation and epidural steroid injection.