TSH & T4 levels: Hi I have just had my annual... - Thyroid UK

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TSH & T4 levels

4sibbs profile image

Hi I have just had my annual test results & have been told I need another blood test in 6-8 weeks can someone help tell me what these results mean, I have been on 50mg Thyroxine for about 20 years always been monitored by the GP but have rarely seen them to discuss anything which is not unusual in th UK. I have not noticed any change in myself.

Serum TSH level - Above Range 9.0 mu/l (0.27 - 4.2) outside reference range

Serum Free T4 level - 15.0 pmol/L ( 12.0 - 22.0)


7 Replies
SeasideSusie profile image


As you can see, your TSH is above range by quite a long way.

The aim of a treated hypo patient generally is for TSH to be 1 or below or wherever it needs to be for FT4 and FT3 to be in the upper part of their respective reference ranges when on Levo if that is where you feel well.

If you develop any hypo symptoms then I'd go back to your GP and ask for an increase in your dose of Levo. Otherwise, see what your new results are like in 6-8 weeks time.

When booking thyroid tests, always book the very first appointment of the morning and fast overnight (water allowed) . This gives the highest possible TSH which is needed when looking for a diagnosis, an increase in dose or to avoid a reduction. TSH is highest early morning and lowers throughout the day. It can also lower after eating and coffee also affects TSH. Also, take your Levo after the blood draw because if you take it before then your FT4 will reflect this and show higher than what is normally circulating. We usually advise 24 hours between last dose of Levo and blood draw so if you take your Levo in the morning then delay until after the test, or if you take it at night then delay that dose until after the test. These are patient to patient tips which we don't discuss with doctors or phlebotomists.

4sibbs profile image
4sibbs in reply to SeasideSusie

Thank you, no-one at my surgery has ever given me any of this information sadly it seems GP's don't have a clue they just prescribe the medication & forget about you, I didn't even get a reminder from them to take the blood test luckily I knew it was due but I had taken my Levo & didn't fast either. The next results will be very interesting

shaws profile image

Shocking results.You have been on an insufficient dose of levothyroxine when the aim is a TSH of 1 or lower with both FT4 and FT3 towards the upper part of the ranges.

This was posted today by one of our Advisers and he is also a Researcher.


4sibbs profile image
4sibbs in reply to shaws

Thank you bit of an eye opener I think I need to have a chat with my GP

SlowDragon profile image

You are EXTREMELY under medicated

Ask GP to test vitamin D, folate, ferritin and B12 as well at next appointment, plus both TPO and TG thyroid antibodies

50mcg Levothyroxine is only a standard starter dose. Dose should be increased slowly in 25mcg steps until TSH is around one and FT4 towards top of range and FT3 at least half way in range

NICE guidelines saying how to initiate and increase. Note that most patients eventually need somewhere between 100mcg and 200mcg Levothyroxine


Bloods should be retested 6-8 weeks after each dose increase

All thyroid tests should ideally be done as early as possible in morning and fasting. When on Levothyroxine, take last dose 24 hours prior to test, and take next dose straight after test. This gives highest TSH, lowest FT4 and most consistent results. (Patient to patient tip, GP will be unaware)

Vitamins likely to need supplementing too. GP should prescribe if they are very low

Come back with new post once you get results and ranges

Your very lucky not to feel very unwell

4sibbs profile image
4sibbs in reply to SlowDragon

Wow thank you for this I had no idea, the only symptom I have had for a long time is that I am always hot & having researched it seems this is more a symptom of an overactive thyroid, it may not be related of course as I am overweight. I will follow your advice & come back with the results. Thanks again

SlowDragon profile image
SlowDragonAdministrator in reply to 4sibbs

Actually many hypothyroid patients have very poor temperature control. Usually it's feeling too cold, but significant numbers feel hot all the time or switch from hot to cold

Weight gain is classic hypothyroid symptom

List of hypothyroid symptoms .....you can probably tick quite a few!


For full Thyroid evaluation you need TSH, FT4, FT3 plus TPO and TG thyroid antibodies and also very important to test vitamin D, folate, ferritin and B12

Ask GP for vitamin and thyroid antibodies testing

Private tests are available. Thousands on here forced to do this as NHS often refuses to test FT3 or antibodies or vitamins


Medichecks Thyroid plus ultra vitamin or Blue Horizon Thyroid plus eleven are the most popular choice. DIY finger prick test or option to pay extra for private blood draw. Both companies often have money off offers.

All thyroid tests should ideally be done as early as possible in morning and fasting. When on Levothyroxine, take last dose 24 hours prior to test, and take next dose straight after test. This gives highest TSH, lowest FT4 and most consistent results. (Patient to patient tip, GP will be unaware)

If antibodies are high this is Hashimoto's, (also known by medics here in UK more commonly as autoimmune thyroid disease).

About 90% of all hypothyroidism in Uk is due to Hashimoto's.

Low vitamins are especially common with Hashimoto's.

Hidden Food intolerances are very common too, especially gluten. So it's important to get TPO and TG thyroid antibodies tested at least once .

Link about thyroid blood tests


Link about antibodies and Hashimoto's



There are almost 90,000 members on here. Thyroid disease is currently extremely poorly managed by NHS. There are over 2 million people in UK on Levothyroxine.

We are working hard to improve things. Read as much as possible about hypothyroidism

See the home website - Thyroid UK


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