test results-no meds or diagnosis

[Happytiredbunny]

I have a consistently low end of normal TSH so tested my thyroid function with an online test

TSH 0.56 mu/L

FT4 13.3 pmol/L

FT3 4.4 pmol/L

After seeing the GP due to the TSH AND ft4 and TSH being low end of normal they did a pituitary function test and the above came back as

TSH 0.84 mu/L

FT4 11.8 pmol/L (low)

FT3 4.1 pmol/L

I have symptoms for overactive thyroid so expected my FT4 levels to be higher… I would just love to have a better understanding of what the results mean, or point towards and what I can do to help!

[PurpleNails Administrator]

Can you please add the lab reference which could be different in each set of tests.

Both the FT4 & FT3 look quite low.

Were both blood test taken in morning after fasting overnight?

Have you ever had thyroid antibodies tested (TPO & TG) ? and also important to test folate, ferritin, B12 & Vitamin D.

TSH is one of the pituitary hormones. To test pituitary function I might expect to see other pituitary hormone as such as ACTH, GH, prolactin, TSH, LH, or FSH.

Do you mean you had a Thyrotrophin-releasing hormone (TRH) stimulation test? It’s not a very common test…..

This would show the show the hypothalamic-pituitary axis response - the TSH should rise, but yours has remained low. Which means the issue is not with your thyroid but the pituitary.

Issues from the hypothalamus or pituitary are referred to as central or secondary hypothyroidism. I can’t confirm this is what your doctors might diagnose, and what function test you had, but it may be one possibility. What has doctor said regarding results?

What symptoms do you have? They can be very varied. Not everyone is the same. EG losing weight when hypo.

[Happytiredbunny in reply to PurpleNails]

These were the first results

Test result

[Happytiredbunny in reply to PurpleNails]

These are the second done by the GP, he was testing other hormones output by pituitary

Second

[PurpleNails Administrator in reply to Happytiredbunny]

The FT4 & FT3 ranges have shifted down & they don’t look terrible.

FT4 28% FT3 48% Lower in range but not under.

Was the test taken at 9. - This is relevant especially for cortisol.

Were the other results as expected? With time of cycle ect?

[Happytiredbunny in reply to PurpleNails]

Was 8:30 after locking myself out of the house and being late for the blood test so I expected high cortisol with stress 😅 I was day 4 of cycle so I think they’re all normal for follicular phase. Growth hormone was requested but I don’t have visibility of them, not sure if they’re not back or abnormal, GP has noted follow up required but I’ve not heard yet, just accessed results through the app

[Happytiredbunny in reply to PurpleNails]

Would the time of day be why the ranges are different?

[PurpleNails Administrator in reply to Happytiredbunny]

Cortisol often has a 3 time range guide, but it just a guide. It needs to be tested in morning when cortisol is highest then the level drops throughout the day.

As the notes say - you should have the test when normally rested & unstressed - the reading should be at higher end of range.

[Happytiredbunny in reply to PurpleNails]

Thank you I really appreciate the information, helps give some context to the numbers hopefully I’ll hear from the GP today about what’s next and I’ll look at more in depth thyroid tests and vit/minerals you mentioned too

[PurpleNails Administrator in reply to Happytiredbunny]

Serum cortisol level 399 mol/L [150.0 - 600.0]Reference range refers to 9am cortisol and

assumes established circadian rhythm. In a

well patient cortisol levels above 400nmol/L

make adrenal insufficiency unlikely.

Midnight and post dexamethasone<40nmol/l.

So given the range & time (and that you were stressed) you’d expect to see levels above 400 & you are 399.

Your doctor is likely to say it’s in range & not be concerned but you might want this investigated further.

[Happytiredbunny in reply to PurpleNails]

Ok thank you for the advice!

[Lalatoot]

Will, the symptoms of overactive and underactive are not as clearcut as the lists you read online. I was overactive, had treatment to kill off my thyroid and am now underactive. I can say from experience that I suffered the same symptoms with both conditions.Low TSH along with low levels of thyroid hormones tends to point to a problem with the pituitary gland . Might be worth doing a Google search of central hypothyroidism and having a wee read.

[Happytiredbunny in reply to Lalatoot]

Thank you I’ll take a look!

[jimh111]

These numbers are very good. TSH has an inverse log normal relationship with T3 and T4, so the TSH reference interval is not linear. A change of TSH from e.g. 0.4 to 0.8 is the same as from 2.0 to 4.0. The median level of TSH is close to 1.5 so your results are quite normal.

You don’t say what your symptoms are, they may be nothing to do with the thyroid.

[Happytiredbunny in reply to jimh111]

Well that sounds quite positive, symptoms are weight loss, poor peripheral circulation, fatigue, menstrual cycle problems, headache one side, dry skin, low mood, quite general.

[Angel_of_the_North in reply to Happytiredbunny]

Might consider asking to get cortisol tested.

[Happytiredbunny in reply to Angel_of_the_North]

Cortisol was 399nmol/L at 8:30 which I think is normal for that time, had been a particularly stressful morning!

[SlowDragon Administrator]

Request GP test vitamin D, folate, ferritin and B12 plus both thyroid antibodies for autoimmune thyroid disease, also called Hashimoto’s

That’s TPO and TG thyroid antibodies

About 90% of primary hypothyroidism is autoimmune thyroid disease, usually diagnosed by high thyroid antibodies

Autoimmune thyroid disease with goitre is Hashimoto’s

Autoimmune thyroid disease without goitre is Ord’s thyroiditis.

Both are autoimmune and generally called Hashimoto’s.

Hashimoto’s frequently starts with transient hyperthyroid type symptoms before becoming increasingly hypothyroid

Low vitamin levels are extremely common when hypothyroid, especially with autoimmune thyroid disease (Hashimoto’s or Ord’s thyroiditis)

20% of autoimmune thyroid patients never have high thyroid antibodies and ultrasound scan of thyroid can get diagnosis

In U.K. medics hardly ever refer to autoimmune thyroid disease as Hashimoto’s (or Ord’s thyroiditis)

Recommended on here that all thyroid blood tests early morning, ideally before 9am

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

bluehorizonbloodtests.co.uk...

Link about thyroid blood tests

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

Link about Hashimoto’s

thyroiduk.org/hypothyroid-b...

Symptoms of hypothyroidism

thyroiduk.org/wp-content/up...

[Happytiredbunny in reply to SlowDragon]

Thank you! I’ll look at getting a more in depth thyroid test once the GP has been in touch if they don’t want to take any more action