I didn't know that dizziness could be a sign of thyroid issues, but if you suspect a low thyroid function you can often detect it via basal body temperature before you can via blood test. I did a quick google search and found this quote:
Dr. Barnes developed the "Barnes basal temperature test" for thyroid
function as long ago as 1942. It relies on a morning, waking,
underarm temperature, which Dr. Barnes believes should average 97.8
to 98.2 to indicate normal thyroid function. Dr. Barnes considers
temperatures below 97.8 a possible sign of low thyroid function.
These are preovulatory temperatures, to be taken on days 2 or 3 of
the period in menstruating women, but on any day for other women,
children, or men. His book states that the underarm basal temperature
is about the same as the oral basal temperature.
Beth wife to Tom and mommy to Therese 11/4/04 Anna Mary 6/15/07 and Veronica 10/20/09