inaccurately diagnosing hypothyroidism question

[spookyscaryskeletons]

This sounds like a dumb question, but I cannot seem to find an answer to it. If someone was prescribed levothyroxine for hypothyroidism by mistake (biotin affecting labs or other weird stuff that made the results inaccurate) how would they know? I have read that the medication does not boost your current thyroid output but replaces it.

I ask because I had routine labs about a year ago and was told I was hypo. They prescribed medication immediately, instead of retesting in a few weeks to confirm. My labs were done during the day, without fasting, and I was taking different supplements, including biotin. I did not know this would impact the results, and the doctor did not mention it.

I am now on 50 mcg of levothyroxine and currently awaiting to be tested again in a few weeks. I have a new doctor and asked this same question, which he didn't answer. Surely I would know if I were not hypo because the medication would have a negative impact, but I thought it would be worth asking. There is still so much I am learning, and it feels like I'm doing it by myself.

[greygoose]

The best thing you can do is ask for a print-out of those first labs where they diagnosed you, see what exactly they tested, and what the results were. I would imagine that your TSH must have been very high for them to start treatment without a second test.

Pretty sure that if you started taking 50 mcg when you didn't need it you would at some point feel it. The TSH wouldn't drop immediately so your thyroid would carry on producing hormone for a while. But it's something that happens so rarely - if ever - that we don't know much about it. Doctors are so reluctant to test for and diagnose thyroid problems that by the time most people start treatment, they're pretty hypo. And, biotind doesn't alway affect the results.

[spookyscaryskeletons in reply to greygoose]

thank you!

[greygoose in reply to spookyscaryskeletons]

You're welcome.

[tattybogle]

hi , it rather depends on what those initial test result were. If they showed only 'sub-clinical' hypothyroidism (NHS use this term if TSH is over range but fT4 is still in range). then a second test should be done to confirm it wasn't a one off/ something else affecting TSH .

However, if the TSH is very over range AND the fT4 is also under range. (NHS call this 'Primary Hypothyroidism' ) then they may not always wait .. because if it's bad enough it needs treating quickly .

Blood tests taken later in the day and after eating breakfast make it LESS likely that you would be diagnosed hypo ... (ie. if your test had been taken early a.m , your TSH wold have been even higher than the one they diagnosed you one.) If you were diagnosed hypo with a daytime test , then you would have been diagnosed 'more hypo ' with an early morning test .

I suspect everyone worries a bit too much about biotin... yes in large quantities it can sometimes have effects on some tests .. but , unlikely to be the sort of effects that would create a false result of both high TSH AND low TF4 that mimicked primary hypothyroidism.

So to put your mind at rest , you first need to find out the actual test results you were diagnosed on .

Ask reception for a printed copy of those TSH and fT4 results [and the lab ranges that come with them]. As long as a GP has seen them already you are allowed to see actual test results ... just ask confidently and of asked why you want them just say .. " for my records"

they will usually say 'oh , they were normal / abnormal' etc .. but you want to the actual numbers eg TSH 10.6 [0.46 - 4.57] fT4 11.2 [12-22]

Also find out if they tested your thyroid antibodies ~ TPOab Thyroid Peroxidase antibodies.

If these were above range they confirm there was an autoimmune cause for becoming hypothyroid., so they know it's not going to just get better.