Did I mess up my blood tests?: Yesterday I went... - Thyroid UK

Thyroid UK

140,927 members166,050 posts

Did I mess up my blood tests?

Tortellini73 profile image
12 Replies

Yesterday I went to have blood tests after being diagnosed with hypothyroidism a month ago. I took 25mcg of levythyroxine (?) before having the test but have now read on here that I shouldn't have done this? My TSH levels were 9.5 last month but are now back to normal but maybe this is why? I am in Italy and I have to book a private appointment to see an endocrinologist to discuss these results and I wondered whether I should redo the blood test beforehand? Thanks.

(My AbTg antibodies were the only value that was flagged up as abnormal at 94 if anyone knows what this means!)

Written by
Tortellini73 profile image
Tortellini73
To view profiles and participate in discussions please or .
Read more about...
12 Replies
helvella profile image
helvellaAdministrator

Antibody tests have variable reference intervals (ranges) and a number such as 94 means nothing on its own. Do you have the reference interval ("normal" range")?

Tortellini73 profile image
Tortellini73 in reply tohelvella

It says the normal range should be less than 4.

helvella profile image
helvellaAdministrator in reply toTortellini73

Well that is indisputably positive!

It is always difficult, impossible, to know what your test would have shown for TSH without you having taken the levothyroxine. However, in earlier stages of autoimmune thyroid disease, levels can vary significantly over short periods of time regardless small doses of levothyroxine.

Most often, Thyroid Peroxidase antibodies are tested - but not Thyroglobulin antibodies. It is perfectly possible for either to be elevated - and not the other one. Did you have both tested?

Also, many believe that once on levothyroxine, you cannot use TSH for dosing. The best is to have FT4, FT3 and TSH - every time. But it depends on your medical system and circumstances whether this can be achieved.

If possible, I would re-test.

Jaydee1507 profile image
Jaydee1507Administrator

If you've only recently started treatmentand are ona low dose of 25mcgs then although it will ffect your FT4 result its probably not going to prevent you getting your much needed dose increase.

Taking Levo just before a blood test won't affect TSH, just FT4.

Testing needs to be after 6-8 weeks on a stable dose to give accurate results. A month is a little too soon.

Tortellini73 profile image
Tortellini73

Thanks. Sorry I wasn't clear. It was diagnosed at the beginning of last month so this is after 6 weeks of treatment.

FT4 came back as 8 (indicated normal range 5.5 - 12).

Anti TPO antibodies came back as less than 1 (less than 9 marked as normal).

Vitamin D came back as 25 (under 12 marked as problematic).

I didn't get ferritin tested this time as it has already been done recently and has hovered between 11 and 18 for the past 6 years! I can't ever get it to go any higher...

I am really hoping for a dose increase as I still feel pretty bad so I was worried that I would be told there was no problem. Hopefully not then!

helvella profile image
helvellaAdministrator in reply toTortellini73

Was FT4 - 8 from the same situation - just after taking a tablet?

You really do need to do something about ferritin. The UK's NICE now says that anything under 30 shows iron deficiency.

helvella - Iron Document

This is a summary of what I have read up and found out about iron supplements over the past few years. I am not in any way medically trained. You are strongly encouraged to check every detail before making any decisions for yourself.

Last updated 02/04/2024

helvella.blogspot.com/p/hel...

Tortellini73 profile image
Tortellini73 in reply tohelvella

Thanks. I'll have a look at that. It was origially picked up by a trichologist because I have lost so much hair - and now what I do have left seems to be breaking off! 🙄 My GP is not interested in ferritin at all and I have been supplementing but it never seems to get over 18 and I don't know why.

Tortellini73 profile image
Tortellini73 in reply tohelvella

Was FT4 - 8 from the same situation - just after taking a tablet? - yes

SlowDragon profile image
SlowDragonAdministrator

Low ferritin will be causing issues

Low ferritin tends to lower TSH as well

Any obvious reason for very low ferritin

Are you vegetarian or vegan

Heavy periods?

cks.nice.org.uk/topics/anae...

Serum ferritin level is the biochemical test, which most reliably correlates with relative total body iron stores. In all people, a serum ferritin level of less than 30 micrograms/L confirms the diagnosis of iron deficiency.

Never supplement iron without doing full iron panel test for anaemia first and retest 3-4 times a year if self supplementing.

It’s possible to have low ferritin but high iron

Test early morning, only water to drink between waking and test. Avoid high iron rich dinner night before test

Stop iron supplements 5-7 days before testing

Meanwhile

Look at increasing iron rich foods in diet

Eating iron rich foods like liver or liver pate once a week plus other red meat, pumpkin seeds and dark chocolate, plus daily orange juice or other vitamin C rich drink can help improve iron absorption

List of iron rich foods

dailyiron.net

Links about iron and ferritin

irondisorders.org/too-littl...

davidg170.sg-host.com/wp-co...

Great in-depth article on low ferritin

oatext.com/iron-deficiency-...

drhedberg.com/ferritin-hypo...

This is interesting because I have noticed that many patients with Hashimoto’s disease and hypothyroidism, start to feel worse when their ferritin drops below 80 and usually there is hair loss when it drops below 50.

healthunlocked.com/thyroidu...

Posts discussing Three Arrows as very effective supplement

Great replies from @FallingInReverse

re ferritin and Three arrows

healthunlocked.com/thyroidu......

healthunlocked.com/thyroidu...

healthunlocked.com/thyroidu...

Great reply by @fallinginreverse

healthunlocked.com/thyroidu...

Iron patches

healthunlocked.com/thyroidu...

Thyroid disease is as much about optimising vitamins as thyroid hormones

healthunlocked.com/thyroidu...

restartmed.com/hypothyroidi...

Post discussing just how long it can take to raise low ferritin

healthunlocked.com/thyroidu...

Iron and thyroid link

healthunlocked.com/thyroidu...

Posts discussing why important to do full iron panel test

healthunlocked.com/thyroidu...

Good iron but low ferritin

healthunlocked.com/thyroidu...

healthunlocked.com/thyroidu...

Chicken livers if iron is good, but ferritin low

healthunlocked.com/thyroidu...

Shellfish and Mussels are excellent source of iron

healthline.com/nutrition/he...

Iron deficiency without anaemia

healthunlocked.com/thyroidu...

Ferritin over 100 to alleviate symptoms

healthunlocked.com/thyroidu...

healthunlocked.com/thyroidu...

Great research article discussing similar…..ferritin over 100 often necessary

ncbi.nlm.nih.gov/pmc/articl...

Low Iron implicated in hypothyroidism

healthunlocked.com/thyroidu...

Really interesting talk on YouTube, link in reply by Humanbean discussing both iron deficiency and towards end how inflammation can also be an issue

healthunlocked.com/thyroidu...

Inflammation affecting ferritin

healthunlocked.com/thyroidu...

Updated reference ranges for top of ferritin range depending upon age

healthunlocked.com/thyroidu...

Thank you for your incredible patience while you have been awaiting the outcome of our ferritin reference range review. We conducted this with Inuvi lab, which has now changed the reference ranges to the following:

Females 18 ≤ age < 40. 30 to 180

Females 40 ≤ age < 50. 30 to 207

Females 50 ≤ age < 60. 30 to 264l

Females Age ≥ 60. 30 to 332

Males 18 ≤ age < 40 30 to 442

Males Age ≥ 40 30 to 518

The lower limits of 30 are by the NICE threshold of <30 for iron deficiency. Our review of Medichecks data has determined the upper limits. This retrospective study used a large dataset of blood test results from 25,425 healthy participants aged 18 to 97 over seven years. This is the most extensive study on ferritin reference ranges, and we hope to achieve journal publication so that these ranges can be applied more widely.

Tortellini73 profile image
Tortellini73 in reply toSlowDragon

Thanks. I have no idea why it is low. I eat red meat (probably too much), liver, take supplements with Vitamin C, have light periods and the highest I have ever got it is still 18! I was tested for coeliac disease years ago but that came back negative too.

SlowDragon profile image
SlowDragonAdministrator in reply toTortellini73

Being hypothyroid results in

A) low stomach acid and makes it much harder to absorb nutrients, especially iron

B) always worth trying strictly gluten free diet with autoimmune thyroid disease

As dose levothyroxine is increased this should help too

Only 5% of Hashimoto’s patients test positive for coeliac but a further 81% of Hashimoto’s patients who try gluten free diet find noticeable or significant improvement or find it’s essential

A strictly gluten free diet helps or is essential due to gluten intolerance (no test available) or due to leaky gut and gluten causing molecular mimicry (see Amy Myers link)

Changing to a strictly gluten free diet may help reduce symptoms, help gut heal

Trying gluten free diet for 3-6 months. If no noticeable improvement then reintroduce gluten and see if symptoms get worse

chriskresser.com/the-gluten...

amymyersmd.com/2018/04/3-re...

thyroidpharmacist.com/artic...

drknews.com/changing-your-d...

Non Coeliac Gluten sensitivity (NCGS) and autoimmune disease

pubmed.ncbi.nlm.nih.gov/296...

The predominance of Hashimoto thyroiditis represents an interesting finding, since it has been indirectly confirmed by an Italian study, showing that autoimmune thyroid disease is a risk factor for the evolution towards NCGS in a group of patients with minimal duodenal inflammation. On these bases, an autoimmune stigma in NCGS is strongly supported

nuclmed.gr/wp/wp-content/up...

In summary, whereas it is not yet clear whether a gluten free diet can prevent autoimmune diseases, it is worth mentioning that HT patients with or without CD benefit from a diet low in gluten as far as the progression and the potential disease complications are concerned

restartmed.com/hashimotos-g...

Despite the fact that 5-10% of patients have Celiac disease, in my experience and in the experience of many other physicians, at least 80% + of patients with Hashimoto's who go gluten-free notice a reduction in their symptoms almost immediately.

Similarly few months later consider trying dairy free too. Approx 50-60% find dairy free beneficial

With loads of vegan dairy alternatives these days it’s not as difficult as in the past

Post discussing gluten

healthunlocked.com/thyroidu...

SlowDragon profile image
SlowDragonAdministrator

You also need B12 and folate tested

Vitamin D on low side at 25ng/ml

Aim to improve to around 40ng/ml

( 100nmol in U.K. units )

Not what you're looking for?

You may also like...

My Story and My recently Blood tests

Hi , Hmmm, let's get started . *NOTE :- All test Results Images Uploaded on Imgur for each date in...
guavas profile image

blood tests

I had my first private Thyroid blood test with Monitor My Health but one thing I didn’t work out...
Lottyplum profile image

Blood Tests

Hi I am asking for your help in how many times does your blood test have to come back abnormal...
darceynjo profile image

Blood Tests

Hi Everyone - I was just wondering if any recently diagnosed people could help out. My doctor has...
plokmijnuby profile image

Blood tests

Today I’ve rang the doctor surgery for the third time requesting my blood test results from the...

Moderation team

See all
helvella profile image
helvellaAdministrator
Jaydee1507 profile image
Jaydee1507Administrator
PurpleNails profile image
PurpleNailsAdministrator

Content on HealthUnlocked does not replace the relationship between you and doctors or other healthcare professionals nor the advice you receive from them.

Never delay seeking advice or dialling emergency services because of something that you have read on HealthUnlocked.