Thyroid UK
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What do I need to ask my GP to check when doing blood work???

Hi guys,

Been on 50mg of Levo since June.

Seeing GP tomorrow for my 2nd set of blood tests. As per previous posts I've been having terrible pains and stiffness in all my joints.

Could you advise on what I need him to check blood wise to start piecing together what's going on with me.

Thanks as always

20 Replies

Fibi1907 You can ask but there's no guarantee they will be done:




TPO antibodies (Thyroid Peroxidase)

TG antibodies (Thyroglobulin)

Are you having the blood draw tomorrow? Thyroid tests should always be done at the earliest appointment of the day, fast from the previous evening (water only) and leave off Levo for 24 hours. That gives the highest TSH when looking for an increase in Levo, plus if the conditions are the same every time you can compare your test results like for like.

You could also ask for

Vit D



to be retested to see how they're going now you're supplementing but it may be a bit early for that. Not worth retesting B12 as result will be skewed, you need to be off B12 supplements for 5 months.


Thanks susie,

My appointment is at 5pm, I take my Levo last thing at night so it's 5 hours short of 24 hours.

I haven't taken any b12 supplements so will still ask for the test.

Out of curiosity I've noticed my pain and stiffness gets so bad in the evenings. Do you think it's because my Levo is due??? I suspect from what I've read in here in need increasing rather than brand change. What do you think???

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Fibi1907 Are you going to have your blood drawn at that appointment this afternoon? If so then cancel it and rearrange it for another day and the first appointment the morning.

It's not long since your diagnosis and you've not yet had enough tests and dose increases to be anywhere near your optimal level. Tests should be done 6 -8 weeks after starting Levo, dose increase, retest after another 6-8 weeks, dose increase if necessary, etc.

Whilst you are still having symptoms and looking for your sweet spot where you feel well, you need to have the highest possible TSH in order to get a dose increase. TSH is highest early in the morning and lowest later in the day. So you need to have your blood drawn as early as possible.

Most people need TSH to be 1 or below or wherever needed for FT4 and FT3 to be in the upper part of their respective reference ranges if that's where you feel well.

I don't know if your pain and stiffness is because your Levo is due, I've never experienced anything like that. But bear in mind that you're not yet optimally medicated and you're vitamins and minerals aren't yet optimal so that might have something to do with it.

I'd probably stay with the same brand of Levo at the moment, see how it goes.

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Hey Susie,

So GP has given me the requested blood tests. I will go first thing Monday to take the tests.

He seems to think I shouldn't have begun vitamin d as a level of 43 in an Asian origin person like myself is sufficient. I'm so confused and wondering if I should stop.

My last blood result is below -

TSH - 3.25 mlU/L 0.3 - 0.5

Thyroid peroxidase - 594 lU/ml 0 - 50

That's all they tested for the last time annoyingly.

I feeling to stop everything except Levo and start again.

GP also testing for R/A for joint pain, I think this can't be right as it's my muscles aching not bones.

My brain is totally frazzled......again

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Are you taking statins? I had to give them up because of muscular pain :(

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Nope 👍🏽


Your thyroid peroxidase indicates you have Hashimoto's which is an autoimmune thyroiditis. Your TSH is still high which indicates that you need to up your dose of what ever thyroid med you are on. I strongly recommend trying a natural desiccated thyroid but everyone is different and many do fine on Levo or Synthroid. some have to add Tirosint or T3 meds. The FTPO group I mentioned in previous reply has a FB page for Hashimoto's as well and they are very good! The first thing you need to do is get off all wheat! It is a factor in the autoimmune response. There is not much difference in the treatment of Hashi's vs. hypothyroidism. You will need to take thyroid meds either way. But knowing what it is makes a difference in your diet and will help your family understand that you have a disease that will make you feel like crap most of the time until you are optimal in meds, supplements and your adrenal glands which will often be over worked trying to make u for lack of thyroid levels in your blood. Good luck!


Forgive me for being naive, but is this disease hashis you mention any more 'serious' or 'dangerous' than having an under active thyroid?

I've requested to join the groups, can't wait to scour the pages.

Thanks for the heads up 👍🏽


Hashimoto's is an autoimmune disease and it can manifest many other symptoms or types of autoimmune symptoms if not kept under control. It is different than plain old hypothyroidism because your body is attacking your thyroid (and potentially other organs or body parts like muscles and joints). It is treated with thyroid meds like hypothyroidism but you need to monitor the TPO antibodies and prevent inflammation (this is where diet can help) that creates a storm of immune response that just makes things worse. Good luck!


Sorry, I forgot to include the lab tests you need. In addition to the TSH, which most doc's test, you will need; Free T4, Free T3, thyroid antibodies=y tests for TPOab (thyroid peroxidaseP and TgAb (antithyroglobulin) for Hashimoto's. Reverse T3 (RT3) is also helpful if you are taking meds but still feel like crap! It is made when your body is getting too much T4 and not using it so it is converted to RT3 which binds to the same site as T3 preventing your cells from using T3, which your body is supposed to use for energy and good health.


Hi Fibi1907 First of all, I have to say that your GP is talking out of a hole in his body that is not his mouth - sorry if that offends but he is talking utter tripe!

Darker skinned people cannot absorb as much Vitamin D from sunlight as white skinned people so need to supplement more. Check out this article on the Vit D Council's website ( ) which is about a study carried out which included people of South Asian ethnicity. The conclusion at the bottom of the page states:

"It is therefore imperative that those with the darker skin types living in areas of the world far from where their skin types evolved supplement with oral vitamin D year round to avoid the startling deficiency states observed in this study. If they want to make their own vitamin D, they likely have to expose more skin and get even longer periods of sun exposure."

So you can see how much your GP knows about that! Just continue with your D3 supplement (and K2) and aim for the recommended level of 100-150.

Your TSH still has a way to go so you are due for an increase in your Levo. The aim of a treated hypo patient is for the 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 if that is where you feel well.

You have high TPO antibodies which means you are positive for autoimmune thyroid disease aka Hashimoto's. In answer to your question to Sylvrfox, no it is not more dangerous or serious than an 'under active thyroid'.

Hashimoto's means that you have antibodies which attack your thyroid. These antibodies will fluctuate, which means your symptoms and test results will fluctuate. Eventually the antibodies will destroy your thyroid. Don't worry, you wont explode or anything, it just means it will wither and die.

Hashi's is the most common form of hypothyroidism. Hashi's isn't treated, it's the resulting hypothyroidism that is treated. There are a few things you can do to try and help reduce the antibody attacks:

1) Adopt a strict gluten free diet. Gluten contains gliadin (a protein) which is thought to trigger autoimmune attacks so eliminating gluten can help reduce these attacks. It's not just wheat you need to give up, or bread and cakes. Read the labels of everything you buy that comes in a package. You'll find gluten in things you didn't even think of. Many members have found that a gluten free diet helps enormously. It's not a quick fix, it can take months to bring antibodies down, but you may find you benefit quite quickly.

2) Some people also find they need to be dairy free.

3) Supplementing with Selenium L-selenomethionine 200mcg daily can also help reduce antibodies (sorry, another supplement).

4) Keeping TSH very low or suppressed is also supposed to help reduce antibodies although that may be difficult as many GPs don't like suppressed TSH.

Don't expect your GP to know any of this, they don't seem to know much about Hashi's, if anything.

Here is some reading about Hashi's, sorry it's more reading but it's better if you know what it's all about, you really do need to know as much as possible about your condition so you can help yourself as it's pretty obvious you wont get much help from your GP:

Now, please disregard the suggestion about natural dessicated thyroid (NDT) and T3 given in the post below. You were only diagnosed in June, it's only 4 months that you have been on Levo and you are still at the beginning of your thyroid journey, you have a long way to go. You don't need any more confusion at this stage. Most hypo patients (over 80%) do very well on Levo alone and it's only when someone has a problem with converting T4 (the storage hormone) to T3 (the active hormone that does all the work) that we need to look at whether there is a better alternative.

So for now, continue as you are. Continue with your supplements. Continue with your Levo but you do need an increase. See what your new results show after your test next week, post the results and members will comment.


Hey SeasideSusie, thanks for getting back to me.

After today I honestly felt like I'm stopping everything apart from Levo and even thought about upping it to 100mg myself!!!

I think I was having a crazy moment.

Thanks for the reassurance. I've been reading but and razing so much conflicting stuff. I feel I wanna just stick with one persons advise but it's impossible as it's all so subjective.

I don't know what to do next 😫😖


No, but was hoping I'd slide into the nurse and get bloods taken today. So despite when I take Levo always go first thing???

I started Levo beginning of July and was retested on Aug so I assumed I could get retested again now????

After all the advise I'm hoping the K2 I started yesterday will kick in soon and help it's the pain 😔


Fibi1907 I don't know who this post is aimed at. If you want a specific person to know you've answered their message you need to click the green reply button directly underneath their post (in the message box) and they will be notified of your response.

Blood for thyroid tests should be taken very early in the morning. Levo should be left off for 24 hours and taken after the blood draw. If you take your Levo at night then leave off the previous night's dose and take it when you get home. If you take it in the morning then don't take it until you get back home.

Blood tests should be repeated 6 weeks after a dose change.

The K2 wont directly help the pain, it's job is to direct calcium to bones and teeth, which is especially important when taking D3 as D3 aids absorption of calcium from food and you don't want it going to your arteries and soft tissues. Optimal levels of D3 should help aches and pains, but it's not like an aspirin, it needs time, it doesn't happen over night.


It wasn't directed at anyone at all. I merely meant I've read so much and asked so many questions and heard know so many possible solutions that it's hard to figure out which way to move forward.

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Fibi1907 I was referring to the post where you've written:

"No, but was hoping I'd slide into the nurse and get bloods taken today. So despite when I take Levo always go first thing???

I started Levo beginning of July and was retested on Aug so I assumed I could get retested again now????

After all the advise I'm hoping the K2 I started yesterday will kick in soon and help it's the pain 😔"

In that post you were obviously answering a question in the first paragraph.

This type of forum can be confusing at times. It's not possible to quote another person's post when answering, and messages tend to get out of sequence so it's not always obvious which reply refers to which previous post.

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How much vitamin D are you taking?

It may be the vitamin D supplements that are making you ache ...but even if it is that doesn't mean you should stop taking them. More likely that it indicates you really need them. ( I have had terrible bone pain in legs - slowly improving)

Very important to get tested for thyroid antibodies. If these are high then you have Hashimoto's. Going gluten free can really help.

Be good idea to get checked for coeliac too, before going gluten free


Your doctor is probably only testing TSH which is a pituitary hormone that tells your thyroid to make more T4. But you can still be hypo if you do not convert T4 into T3, the active form our body uses to feel well. This can occur for many reasons but you need to test for T4,T3, and RT3 (reverse T3) in order to see if you are converting. If your T3 levels are low, or your RT3 levels are high this can tell you many things. If T3 is low you are not converting, if it is high but RT3 is high your cells will not take in the T3 because the RT3 is binding to the site that the T3 is supposed to bind to and your cells can't get the T3 in. Levothyroxine or Synthroid are only T4 medication so if you don't convert it is useless. You need to get a medication that contains T3 as well. I am not sure if there is a synthetic form but natural dessicated thyroid like Armour or WP do contain T3. Most doctors are brain washed by drug reps and will not prescribe those natural forms but if you insist or look for a doctor that will, you will feel amazingly better once you are on them. That is if you are not converting. If you have high RT3 you need to add T3 medications to raise the levels and to knock the RT3 off the sites. There is a great Facebook group called FTPO-thyroid issues that has great admins that will go over your tests and share patient experience and knowledge! There is also a book called STTM-Stop the Thyroid Maddness that is a wealth of information for thyroid patients. Good luck! The FTPO group is a closed group and you need to hit the "ask to join" button so they can look at your facebook page to see that you are not a multilevel marketer and then they will approve your request to join.


Absolutely fantastic information!!!!!!

Can't thank you enough. I'm going to join that group on FB now.

My last bloods didn't include testing for T3, T4. I have added them to my reply to seasidesusie above.

Have a look, I'd appreciate anyone's helping me understand things better. I don't think my gps know what they are doing.


If you find you aren't converting well you need to have mineral sect looked at as they are essential for conversion. Many of us take supplements and it does help a lot but doesn't happen overnight. These things have to be in place to get any form of thyroid meds to work properly.


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