Did you also have the Thyroglobulin Antibodies (TgAb) tested? It's odd that I would have suggested that you only have TPOab tested since both are markers for Hashimoto's... How long ago was that? It's possible that if you have them tested now, they'd be higher than they were at that time.
Are you having Free T4 and Free T3 tested or Total T4 and Total T3? They aren't the same tests and don't give the same information.
Have you had a thyroid ultrasound to determine if you have any nodules on your thyroid? Those can be an indication of Hashimoto's, as well as the antibody tests.
Hashimoto's can take years to do enough damage to cause actual thyroid hormone levels to go out of range, even though we can have symptoms throughout that time. I believe I had it for as long as 20 years before my TSH and Free T4 actually went out of range. When they did, it happened quickly and I understood why I felt like death warmed over.
I, too, had low heart rate, shortness of breath, etc when I was severely hypo. Just because your T4 and T3 are in the "normal" range doesn't mean they are adequate. If you aren't getting the Free T4 and Free T3, you aren't getting up to date tests and if your results are too low in the ranges, your levels are not adequate.
If you can post a couple sets of your latest results, with their corresponding reference ranges, we can better assess the labs that are being ordered and their results.
Hi, I had serious shortness of breath and bradypnea (down to 6 breaths a minute) due to hypothyroidism and my pulse oximeter reading was normal.
I had hypoventilation - a reduced amount of air enters the alveoli in the lungs resulting in decreased levels of oxygen and increased levels of carbon dioxide in the blood.
To quote Wikipedia...
"Pulse oximetry measures solely hemoglobin saturation, not ventilation and is not a complete measure of respiratory sufficiency."
Do you have you current lab results?
And another thing I am really afraid of, can this "air hunger" I keep experiencing not being able to catch a breath of relief unless I yawn, can this be brain hypoxia??? I have gone to doctors and ER before when short of breath....when feeling like I am starving for air, and they're checking my oxygen with a monitor placed on my finger to measure oxygen!!! Is that a safe thing for measuring oxygen to the brain? Is it the same thing? I've experienced these symptoms for over 3 years now. :'( My biggest fear is not having oxygen to brain or is what I'm experiencing just off signals from thyroid to heart to brain??? :'( Thanks so much to anyone who can help me better understand and answer this.