TSH Levels and determining medication?

TSH Levels and determining medication?

I've attached a list of my symptoms above for reference.

Alright...Here's my question. What does the TSH test specifically look for? Is it looking for a combination of T3 and T4? And if it's low/high, how do they determine what medication is needed without testing the individual levels?

I ask because my doctor has me on Levothyroxine and it does absolutely nothing for the symptoms that I am having (have been taking it for over a year). I noticed that Levothyroxine is supposed to be for T4, but I have LOW levels of T4 .9 (standard 0.7 - 1.5 ng/dL), so why would I be put on T4 medication?

I am trying to understand so that when I go back to the doctors I can have a discussion about other medications that may actually do something positive for once. I should also mention that my TSH levels keep fluctating. Last June (2013) it was .67 and now it's up to 4.22.

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4 Replies

  • The Thyroid Stimulating Hormone (TSH) test simply determines how much TSH is produced by your pituitary gland to instruct your thyroid to produce Free T4 (FT4) which is a storage hormone that converts to Free T3 (FT3) in the liver.

    It's a disgrace that GPs and labs are only testing pituitary output of TSH which gives no indication of FT4 and FT3 levels or whether production of FT4 and conversion to FT3 is even happening.

    80% of hypothyroid patients do well on Levothyroxine (T4) but the 20% who don't, myself included, require Liothyronine (T3) in addition or instead. Some of that 20% are unable to tolerate T4 and take T3 only and others are unable to tolerate any synthetic replacement and use natural dessicated pig or bovine thyroid (NDT).

    Your low FT4 could mean that you are struggling to convert to FT3. This could be because you are under medicated (you don't say what dose you are taking) or because you aren't converting.

    Your rising TSH could also be due to under medication or because of lymphocyte attack on your thyroid gland. Ask your GP for Thyroid Peroxidase Antibody (TPoAb) and Thyroglobulin Antibody (TgAb) blood tests to check for autoimmune thyroiditis (Hashimoto's). Treatment is the same as for non-autoimmune hypothyroidism but ownership of one autoimmune disease predisposes one to others which may be avoided or mitigated by dietary changes ie gluten-free, dairy-free, lactose-free &/or sugar-free.

    Ask your GP for a coeliac screen to check gluten-intolerance and to test your ferritin, vitD, B12 and folate. These are often deficient or low in range in hypoT patients and symptoms can be mistaken for hypoT symptoms.

    Finally, if you are on an optimal dose of T4 but still suffering symptoms, ask for a trial period of T3 in addition to reduced dose of T4 to see if symptoms improve. If GP won't prescribe tell him/her you'll buy it on the internet. They hate that and often relent ;)

    Be sure to always request print outs of your test results with laboratory reference ranges or make an appt to view your results and make notes if they want to charge more than a couple of quid. GP's notion of normal often means very low within range and supplementation is needed although it won't be on prescription.

  • Thanks, I appreciate it. The doctor has me currently on 50mcg for 4 days and then 75mcg for another 4 days. She did this because my levels came back at 4.22, and I asked her if we should increase the dosage because it was apparent my hypothyroidism isn't under control. Which to me seems counter-intuitive as one day it could be barely getting enough and the next it's not anything nearly enough to function properly. All of my vitamin levels have come back normal. I tried going gluten free and it didn't make any type of change, so I'm fairly positive that's not it.

    I'll definitely ask for the Thyroid Peroxidase Antibody (TPoAb) and Thyroglobulin Antibody (TgAb) tests when I see her next to rule this out.

    I've been battling these horrible symptoms now for years and it's actually gotten a lot worse here recently.

  • Your current dose of levothyroxine is quite low. The problem with a low dose is that the body has a control mechanism to regulate its production of thyroxine (T4). When you take smaller amounts of levothyroxine the control mechanism will detect this and make a bit less of its own, meaning that the amount of thyroid hormone in your body stays the same and you do not feel any better.

    Many people need to keep increasing their dose to feel better. Some doctors panic about TSH going too low, but a knowledgeable doctor will know that it is ok even if TSH goes to zero.

  • I think you're very under medicated. I'd be inclined to increase to 75mcg/100mcg on alternate days and retest in 4 weeks. That's still a modest dose and should be increased if your TSH hasn't gone down to just above/under 1.

    T4 is long acting so alternating dosing doesn't cause fluctuations except in very sensitive people. If you stopped taking it you probably wouldn't notice for 2/3 weeks the same way you don't instantly notice dose increases.

    I spit on your GP's normal with respect to vit tests. Get a print out.

    Keep eating gluten until you test for coeliac. If you are positive and do decide to go g-f you need to do it for at least 3 months to feel benefits and may have withdrawal symptoms too. I'm not g-f myself because I'm surgically thyroidless so Hashi's no longer a problem but a lot of Hashi and hypothyroid px do reap benefits from going g-f.

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