Welcome to our forum and don't worry about your lack of knowledge as it would appear most medical personnel have very little knowledge either.
I will advise you of the most important thing when you are having a blood test and that it has to be the very earliest appointment, fasting (you can drink water). If yours is later, alter your test date and time. Also allow a gap of 24 hours between your last dose of levo and the test and take afterwards. This helps keep the TSH at its highest and prevents a reduction in our prescriptions.
The thyroid gland and its hormones enable our metabolism to run smoothly, i.e. every single receptor cell in our body requires the hormone T3 to function optimally . Our brain/heart contain the most receptor cells.
When we have insufficient thyroid hormones circulating we get clinical symptoms:-
If we have hypothyroidism the doctor will prescribe levothyroxine which is a synthetic T4 hormone.
We are provided with a starting dose of 50mcg and have a blood test every six weeks with an increase of 25mcg until our symptoms are relieved and the TSH is 1 or lower. Not higher as many medical professionals believe. Some stop increasing dose when the TSH reaches somewhere within the range which is probably about 5. In the UK, they make us wait until the TSH is 10 before prescribing.
So, on this forum, we educate ourselves by asking questions and learning slowly.
Most doctors only take notice of the TSH - (Thyroid Stimulating Hormone) which begins to rise as our thyroid hormones are failing. It is from the Pituitary Gland. The aim then is levothyroxine to bring the TSH to around 1 or below. Most doctors think 'somewhere' in the range is fine but it doesn't improve our health. T4 - levothyroxine - converts to the Active thyroid Hormone, liothyronine (T4).
A healthy thyroid gland produces T4 and T3 - T4 is levothyroxine and T3 is liothyronine and also calcitonin.
When we were prescribed Natural Dessicated Thyroid hormones before levothyroxine and blood tests were introduced, we only got prescribed NDT.
Blood tests can include TSH, T4, T3, Free T4, Free T3 and thyroid antibodies but rarely are all of these tested and some members get their own blood tests.
We also have to have an optimum B12, Vit D, iron, ferritin and folate as deficiences also cause symptoms.
always get a print-out for your own records and you can post if you have a query.