Help understanding why my T4 is in range but my TSH is high

[HeatherParker]

Would like a little help understanding my recent lab results

T4 12.9

TSH 5.76

I take 175mg levothyroxine and 10mg Liothyronine

[SeasideSusie Remembering]

HeatherParker

To get the most accurate results we always advise:

* Blood draw no later than 9am. This is because TSH is highest early morning and lowers throughout the day. If looking for a diagnosis of hypothyroidism, an increase in dose of Levo or to avoid a reduction then we need the highest possible TSH

* Nothing to eat or drink except water before the blood draw. This is because eating can lower TSH and coffee can affect TSH.

* If taking thyroid hormone replacement, last dose of Levo should be 24 hours before blood draw, if taking NDT or T3 then last dose should be 8-12 hours before blood draw. Adjust timing the day before if necessary. This avoids measuring hormone levels at their peak after ingestion of hormone replacement. Take your thyroid meds after the blood draw. Taking your dose too close to the blood draw will give false high results, leaving any longer gap will give false low results.

* If you take Biotin or a B Complex containing Biotin (B7), leave this off for 7 days before any blood test. This is because if Biotin is used in the testing procedure it can give false results (most labs use biotin).

These are patient to patient tips which we don't discuss with phlebotomists or doctors.

Did you do your test this way, particularly the time gaps between last doses of Levo and T3 and blood draw? This is very important when interpreting results.

Also, to be able to interpret them we need the reference ranges that come with your results as these vary from lab to lab, eg

TSH: 2.5 (0.27-4.20)

Can you please add the ranges.

We know that your TSH will probably be over range as we don't tend to see ranges go above about 5. Your TSH level is very unusual for someone taking the doses of thyroid hormone you take. Taking Liothyronine tends to lower, even suppress TSH, and even if you didn't take liothyronine and only took Levo with the dose you take one would expect to see your TSH level near the bottom of the range.

Was FT3 tested? It should be when taking liothyronine and your endo should know this, otherwise how would he know how to decide on a dose and adjust it?

[radd]

HeatherParker,

You look very under medicated in spite of a good dose of meds.

Are you taking meds with only a glass of water, 30-60 minutes away from food, 2 hours away from other meds/supplements and 4 hours away from supplemented iron & calcium?

The other possibility for these results is a high level of binding proteins preventing good levels of “frees”, possibly caused by elevated oestrogen, even testosterone? This again would make TSH elevate in an effort to encourage more ‘free’ thyroid hormone. Are you peri-menopausal or taking HRT?

You havent given ranges (numbers in brackets) and for a more comprehensive picture you would also need FT3 tested but given that assumed high TSH and low FT4 I think it safe to assume FT3 levels are low also. Do you have hypo symptoms?

SeasideSuzie has offered info re test timings, and possible assay interference.

[SlowDragon Administrator]

Obviously just testing TSH and Ft4 is completely inadequate

For full Thyroid evaluation you need TSH, FT4 and FT3 tested.

Very important to test vitamin D, folate, ferritin and B12 at least once year minimum

Low vitamin levels are extremely common, especially after Graves

What vitamin supplements are you currently taking

Recommended on here that all thyroid blood tests early morning, ideally before 9am last dose levothyroxine 24 hours before test

On T3 or NDT - day before test split daily dose into 3 smaller doses, spread through the day at approx 8 hour intervals, taking last 1/3rd of daily dose 8-12 hours before test

This gives highest TSH, lowest FT4 and most consistent results. (Patient to patient tip)

Private tests are available as NHS currently rarely tests Ft3 or all relevant vitamins

List of private testing options and money off codes

thyroiduk.org/getting-a-dia...

Medichecks Thyroid plus antibodies and vitamins

medichecks.com/products/adv...

Blue Horizon Thyroid Premium Gold includes antibodies, cortisol and vitamins by DIY fingerprick test

bluehorizonbloodtests.co.uk...

If you can get GP to test vitamins and antibodies then cheapest option for just TSH, FT4 and FT3

£29 (via NHS private service ) and 10% off down to £26.10 if go on thyroid uk for code

thyroiduk.org/getting-a-dia...

monitormyhealth.org.uk/

NHS easy postal kit vitamin D test £29 via

vitamindtest.org.uk

[kiefer]

First thought is an absorption issue. There are two basic causes:1) You're eating foods containing minerals that bind with levothyroxine, lowering the absorption down significantly.

2) The pH of your stomach acid is too high. Levothyroxine has a better chance of getting into your bloodstream when the pH of your stomach fluid is low. It's actually absorbed in the small intestine but has to be in an ionized (dissolved) form first. One solution (if this is the case) is to take 500mg of Ascorbic Acid (not Sodium Ascorbate, which is buffered). A study showed that this was effective in lowering stomach pH and enhancing absorption of levothyroxine with improvements in TSH, Free T4 and T3 levels.

pubmed.ncbi.nlm.nih.gov/246...

The second is the timing of the testing. If you want to know what the Peak levels are of Free T4 or Free T3, then you would want to take your thyroid medicine within 4 hours of the blood test. If you want to know the Trough (which is what everyone here advocates) then you'll want to take the last dose of T4 about 24 hours and T3 about 15 hours prior to the blood test.

The third is that the medication you're taking is degraded. There was time when a 100mcg tablet of Synthroid only contained 82mcg. If your medication is kept in a bathroom with a shower, it can very easily be degraded by the heat and moisture. If you live in an environment that is hot (throughout your home) then you can put your thyroid medication in the refrigerator. There was once a drug called Thyrolar that had to be kept refrigerated.

The fourth is simply forgetting to take the thyroid medication consistently.

I saw a chart somewhere that doctors use to determine non-compliance with regards to a thyroid patient. If the amount of levothyroxine doesn't show a certain level of Free T4 then the conclusion drawn is that the patient is not taking their meds OR maybe they're taking them with food that binds with the T4. I've listed a few other possibilities.

It's clear that you're not taking mega-doses of Biotin since your TSH is high and your Free T4 is quite low. Usually, those who take mega-doses of biotin show that the TSH is very low and the Free T4 and Free T3 are very high.

Just out of curiosity, what are your current symptoms?

[WaterLou]

I like Seaside Susie’s response. In addition, it sounds like you need a comprehensive lab analysis, CBC, CMP, full thyroid panel and hormone panel. In the short run try splitting half of your T3 dose between morning and bedtime. Follow your HR and temp, plus how do you “feel”?