TSH query

[BetterDayzAhead]

Morning

Just very quickly before I speak with GP

Should a prescription of 50mg Levothyroxine cause a drop in TSH from 2.4 to 1.4 (0.27-6)

Why would it drop if T4 still 11.5 (12-22) and prior to this medication was 13 (12-22)

Thank you.

K x

[SeasideSusie Remembering]

BetterDayzAhead

Should a prescription of 50mg Levothyroxine cause a drop in TSH from 2.4 to 1.4 (0.27-6)

Generally, yes.

Why would it drop if T4 still 11.5 (12-22) and prior to this medication was 13 (12-22)

When was last dose of Levo taken before the test?

How long have you been on this dose? Usually requires at least 6-8 weeks for levels to stabilise after an increase.

Are you taking your Levo as we advise, ie one hour before or two hours after food, with water only and water only either side, certain things can affect absorption of Levo (it's a very fussy hormone) such as coffee and possibly other caffeine containing drinks, high fibre foods, other medication or supplements (which must be taken at least 2 hours away from Levo and some need 4 hours).

Did you take a supplement containing biotin in the 7 days before this test?

[BetterDayzAhead in reply to SeasideSusie]

Thank you ~Levo was taken 24 hours before this test. No biotin. Always take my Levothyroxine in the way this page advises. Thank you. I was under the impression if free thyroxine was low the TSH should be higher through the range to stimulate more production? Its dropped from 2.4 to 1.28 actually and tange (0.27 to 4.2)

[SeasideSusie Remembering in reply to BetterDayzAhead]

I was under the impression if free thyroxine was low the TSH should be higher through the range to stimulate more production?

Yes but it's still early days and how long between dose increase and doing this test? Also, see PurpleNails' reply.

[PurpleNails Administrator]

Did FT3 increase that might account for lower TSH even with a drop in FT4 ?

[BetterDayzAhead in reply to PurpleNails]

Hi, Free T3 only went from 4 to 4.1 (3.1~6.8) the blood tests were 9 weeks apart.

[SeasideSusie Remembering in reply to BetterDayzAhead]

So your TSH is responding to the fact that you're taking exogenous T4 but as the FT4 has not improved you're not yet on the correct dose of Levo. You need an increase. 50mcg would rarely be enough for any hypothyroid patient, the average is around 125-150mcg.

[SlowDragon Administrator]

50mcg levothyroxine is only the standard starter dose

Looking at previous post you only increased dose a month ago?

Dose levothyroxine should be increased slowly upwards in 25mcg steps until symptoms are improved and typically Ft4 is at least 50-60% through range

As per previous posts

Have you had vitamin D, folate, ferritin and B12 levels tested

What vitamin supplements are you currently taking

Have you had three antibodies tested

Or coeliac blood test done

[SlowDragon Administrator]

Approx how much do you weigh in kilo

guidelines on dose levothyroxine by weight can help argue for next dose increase up to 75mcg daily

Even if we frequently don’t start on full replacement dose, most people need to increase levothyroxine dose slowly upwards in 25mcg steps (retesting 6-8 weeks after each increase) until eventually on, or near full replacement dose

NICE guidelines on full replacement dose

nice.org.uk/guidance/ng145/...

1.3.6

Consider starting levothyroxine at a dosage of 1.6 micrograms per kilogram of body weight per day (rounded to the nearest 25 micrograms) for adults under 65 with primary hypothyroidism and no history of cardiovascular disease.

Also here

cks.nice.org.uk/topics/hypo...

gp-update.co.uk/files/docs/...

Traditionally we have tended to start patients on a low dose of levothyroxine and titrate it up over a period of months. RCT evidence suggests that for the majority of patients this is not necessary and may waste resources.

For patients aged >60y or with ischaemic heart disease, start levothyroxine at 25–50μg daily and titrate up every 3 to 6 weeks as tolerated.

For ALL other patients start at full replacement dose. For most this will equate to 1.6 μg/kg/day (approximately 100μg for a 60kg woman and 125μg for a 75kg man).

If you are starting treatment for subclinical hypothyroidism, this article advises starting at a dose close to the full treatment dose on the basis that it is difficult to assess symptom response unless a therapeutic dose has been trialled.

BMJ also clear on dose required

bmj.com/content/368/bmj.m41

healthunlocked.com/thyroidu...

jamanetwork.com/journals/ja...

[BetterDayzAhead in reply to SlowDragon]

I'm 92 kilos (22kilo on since 2017 due to a mix of thyroid issues and Surgically managed conditions) So 1.6 x 92 is 147, 150mg is a therapeutic dose for my weight is thatabout right?

FYI, the last heated discussion I got with my GP there was repetitive referencing by her of her medical guidelines book.

This was to test my T4 and T3 yet she was adamant to only test TSH hence me going privately and getting bloods done that included T4 T3 and TSH.

We ended up with me on a weekend increase yes, I said that right , a Saturday Sunday increase from 25mg to 50mg!

This was all the battle I had in me that day and went away perplexed.

Privately;

I was lucky enough to have a nurse under Rheumatology (I'm negative for Rheumy conditions) kindly add on the bloods I requested.

My issue is also that the GP may not increase my Levothyroxine going by this medical book she kept referring to. Am I going to be able to source my own Levothyroxine , Im in the UK?

This has went on too long, since Hysterectomy in March 2018 I have had a T4 of 10.3, 13, 11.5, 13.05 (12-22) so it keeps just dropping into range then falling out of range and TSH has stayed at 2.02 to 2.04 until the recent test its 1.28 (0.27 to 4.2)

T3 ~ 4.1 (3.1~6.8) thats stayed the same basically 4 or 4.1

I'm also wondering as a chronic pain patient does inflammation affect our available thyroid hormones?

Many thanks.

[SlowDragon Administrator in reply to BetterDayzAhead]

Your GP is just TSH obsessed….so many are

Most important results are always Ft3 followed by Ft4

Dose levothyroxine should be increased SLOWLY Upwards in 25mcg steps (or even 12.5mcg )

Levothyroxine doesn’t top up failing thyroid, it replaces it

Thyroid levels should be tested 6-8 weeks minimum after each dose increase

Most people when adequately treated will have Ft4 at least 50-60% through range

When under medicated we frequently develop low stomach acid, this leads to poor nutrient absorption and low vitamin levels

Low vitamins tend to lower TSH

Have you had thyroid antibodies tested ever?

About 90% of primary hypothyroidism is autoimmune thyroid disease also called Hashimoto’s usually diagnosed by high thyroid antibodies

Absolutely essential to regularly retest vitamin D, folate, ferritin and B12 at least once a year

What vitamin supplements are you currently taking

Strongly recommend getting full thyroid and vitamin testing done before booking a consultation with thyroid specialist endocrinologist

Email Thyroid U.K. for list of recommended thyroid specialist endocrinologist and doctors

[e-mail]

Roughly where in U.K. are you

Bowel surgery ?

Constipation is extremely common hypothyroid symptom

Link about thyroid blood tests

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

Link about Hashimoto’s

thyroiduk.org/hypothyroid-b...

List of hypothyroid symptoms

thyroiduk.org/if-you-are-un...

[BetterDayzAhead in reply to SlowDragon]

Thank so much slow dragon. Why do you put T3 more important to test then T4?

If I go by any of my results, its only ever the T4 that has been out of range so I've been more inclined to push for the T4 test.

Is the T3 the one to do with conversion of thyroxine or is that T4?

Thanks so much.

Yes I've had a 25mm polyp (benign thank goodness) removed from my ascending colon on 5/5/22 which supposedly was causing me rectal bleeding, pain ad bowel spasming.

Actually very much have had a shift from loose stool to constipation in the last 10 to 12 months.

Ps...is there a quick way to work out the percentage through range T3 and T4

Many Thanks. Have a lovely rest of the day.

K.

[SlowDragon Administrator in reply to BetterDayzAhead]

So even more reason to get iron and ferritin tested if been loosing blood

On levothyroxine we must have GOOD vitamin levels

Ferritin an£ folate at least half way through range

Serum B12 at least over 500

Vitamin D around 80nmol and around 100nmol maybe better

Ft4 and Ft3

Levothyroxine is Ft4 and is basically inactive

Ft4 is converted in cells to Ft3 - active hormone

So testing Ft4 shows how much levothyroxine you are taking…….most people when adequately treated will have Ft4 at least 50-60% through range…..often higher

Once Ft4 level is at high enough level….when on a decent level of levothyroxine

Then it’s Important to test both Ft4 and Ft3

Ft3 result in comparison to Ft4 shows how well or badly someone converts Ft4 to Ft3

In an ideal world…..on adequate dose levothyroxine…..both Ft4 and Ft3 will be similar % through range at 60-80%

In reality we see many people whose Ft3 remains rock bottom as they have poor conversion

Improving low vitamin levels can help improve conversion rate

Short film explaining interaction of vitamin levels etc

drbradshook.com/understandi...

[BetterDayzAhead in reply to SlowDragon]

That makes alot of sense re T3 and T4. I understand the relationship of Levothyroxine now to the T4 level.

I am injecting B12 yet the other vitamins I've slept in on, I know its never an excuse but life has got so hectic I've dropped the ball a bit re vitamins.

Il start again tomorrow.

Il watch this film.

The through range references are really helpful too so thank you much.

K x

[BB001 in reply to BetterDayzAhead]

Quick way to work out percentage through range?Use this tool (thank you to the person who's husband developed it!)

thyroid.dopiaza.org/

[BB001 in reply to BetterDayzAhead]

Available thyroid hormones affect chronic pain in my experience.

Test as early as you can in the day to catch TSH at its highest, fT4 at its lowest.

[BetterDayzAhead in reply to BB001]

Do you feel low thyroid hormones affect you by feeling more sensitive to pain?I'm really struggling at the moment with both.

I can't get cut a break.

Now on to GP by letter explaining why I'm asking for my Tramadol 6 days early this month considering I have a 3cm bowel resection and due another Surgery on 31st!

Absolutely a shambles the way the NHS is going.

K.

[BB001 in reply to BetterDayzAhead]

I get joint pains when my T3 falls low. I also get less able to cope with pain.

[tattybogle]

So we already know (from your TSH /fT4results before you started levo) that your TSH doesn't rise as much as expected when your fT4 is low..... so to some extent it's safe to assume your TSH is not terribly 'reliable' ... or at least that it's 'a bit slow '

On your last post you were on 25 (5 days) and 50 at weekends .

Have you since been increased to 50mcg every day ?

If so, you need to be taking that dose for 6 weeks before blood tests can tell you anything useful.

So if you let us know the dates of any dose changes, and blood test results for each dose you were on.. then it's easier for us to explain what is going on.

but basically , any time you add some more T4 from levo, you can expect the TSH to go lower. (but it might take up to 6 weeks to get round to it)

However, when you first add T4 from Levo the fT4 doesn't necessarily go up as you'd expect ( or it might go up briefly , but then by the time you have the 6 week blood test ,it's the same or even lower than it was before) ....because...

very simplified example:

thyroid itself is making '10' ( because TSH is asking it to )

you add '5' from levo .

so for a short while you have '15'

But that means the TSH lowers ..and less TSH means the thyroid itself gets 'turned down' a bit ... so then the thyroid is only making '5' or even '4'

So then you have '4' from thyroid + '5' from levo = '9' ..... less than you started with.

as doses are increased this balancing effect even's out, until eventually you are taking 'enough' to get fT4 level that is more than you got from your own thyroid.

This explains why you can't usually just 'top up' a low T4 with a very low dose of levo.... if you are going to replace thyroid hormone effectively .. you usually have to replace more than you expect ..and why doses need to be increased until the balance is found.

~ So your TSH is lower as expected (if levo was increased)

~ And your lower fT4 probably just indicates that the dose needs increasing a bit more because you own thyroid has taken it's foot off the accelerator now that the TSH is lower.

~ And your latest TSH isn't as high as we might expect for a 'below range' fT4 ... because it wasn't in the first place, before you took any levo .. so it's obviously just not very good at going up like it's supposed to..

It helps to remember that TSH and fT4 levels change on different timescales, so results sometimes don't seem to make sense.

TSH result is basically telling you 'what was happening over a week ago' ( and for some with 'slow' TSH ,it could be a lot longer than that .ie, many weeks , or even months )

fT4 result is basically telling you 'what was happening in the last few days'

So they don't always seem to be saying the same thing ...

[SarahJane1471 in reply to tattybogle]

That is great explanation tattybogle

[BetterDayzAhead in reply to tattybogle]

That is a great explanation. It may take me several reads to understand the 10 + 5 and so part. I'm just struggling a bit with it all.

Yes ~ you are right, I got a weekend increase and just went ahead and took 50mg everyday because I'm struggling do much and sleeping so long. I have a partner at home caring for my disabled son and myself and I had bowel EMR surgery on 5/05/22 so went above GP's head and took the 50's. My circumstances are pretty grim in terms if health and energy levels.

I've been on 50 since 12/04 so the bloods on 13/05 may not reflect the increase?

I always do a morning blood test before anything taken orally and 24 hrs approx sonce last thyroid medication.

[tattybogle in reply to BetterDayzAhead]

yes , so it's only 5 weeks yesterday that you increased to 50 mcg , and assuming its at least few days ago that you had that blood taken.... a)yes, it's a bit too soon to expect either fT4 or TSH to really be telling you the truth about the effect of a settled 50mcg dose .

b) surgery in itself could potentially have done ? who knows what to both levels .. and they may take a while to settle down again after that.

~ See what happens to TSH/ fT4 /and T3 and Reverse T3 during severe illness in the rather mad diagram below,,, it's a reasonable assumption that the body may have a similar reaction to someone putting it to sleep and chopping bits out of it and sewing it back up again.~

p.s i agree with your decision to go up to 50mcg... so many GP's seem to be either ridiculously over cautious with initial increases , or go the opposite extreme and yank settled doses up / down massively when just a small tweak was required .... but asking you to increase from 25mcg a day to (effectively) 32mcg a day was, rather taking the piss. when your fT4 was so low....and in your case they (should) mostly be guided by fT4 ,because they (should) already suspect your TSH is a bit 'dud'.

..

[tattybogle in reply to tattybogle]

excellent % through range calculator thyroid.dopiaza.org/

(kindly put together for us by the curry loving husband of 'FancyPants' )

[BetterDayzAhead in reply to tattybogle]

Thanks so much Tatty. I really feel like if I wasn't wakened I'd sleep as if I'm in a coma!

I really didn't think it took as much as 6 to 8 weeks to see the settling of an increase of a new dose.

Il try and get these bloods re~done when I have the energy to brace this fight with the GP!

Yes I'd a piece of bowel taken out aprox 3.5cm resected, so the thyroid may have went a bit doolally. I am just so tired its like a fog of something pushing downwards like literally pushing eyelids downwards like they are shutters trying to remain open when the switch has been set to close shutters.

Thanks for the calculator and the graph.

I also have this question prepped for GP...

"How did you prescribe patients thyroxine in the past when their TSH and Thyroid bloods were not available? "

There really has to be more of a symptom based diagnosis for patients than reading a bloody THS level.

4 years is a long time to be going in and out of range of T4.

Thats 4 years that Is documented.

I've had these symptoms 33 ears since I was 10.

Thanks so much

K.

[Suvi8901]

Careful!

Do you mean 50 micrograms rather than 50 mg?

1 milligram is actually 1000 times more than 1 microgram.

Or 1mg=1000μg/1000mcg.

The doctor must know this. Look at the box again!

[BetterDayzAhead in reply to Suvi8901]

Sorry thats my error. 50mcg. I will use that from now on now that I know! I checked the box its definately micrograms! Thank you for that. I like to be correct so thank you for pointing this out to me Suvi.

Ta 🤗

K.