My daughter who is 20yrs old has been feeling unwell for sometime now and has recently been tested for a thyroid problem.
Her test results came back and were;
TSH 1.08 mU/L (0.35-5.00 U)
Free T4 12.0 pmol/L (9.0-21.0 U)
The doctor has said these results are fine and need no further tests however i think they are both on the low side of the range.
Can anyone provide some advice on the readings please.
Kind Regards
Gillian
Hi alpaco,did they not test the t3 levels?Im in Northern Ireland and my GP only tests for tsh and t4.I sent away for a home testing kit to measure t3.It’s the most important one.
Hi SovietSong
Thank you for your speedy response.
She wasn't tested for for T3 im a going to look into this.
Thanks Again
Im no expert,far smarter people on here and very helpful they are too.I got home test kit from Monitor My Health which was recommended on here.There are discounts available also if I recall.Hope your Daughter gets sorted asap.
TSH (Thyroid Stimulating Hormone) is most commonly around 1 (ish) in healthy people . so that result is not low . healthunlocked.com/thyroidu... (tsh-levels-in-healthy-people-with-no-known-thyroid-disease)
The fT4 result is FT4: 12 ( 9 - 21) 25 % through range (calculator thyroid.dopiaza.org/ )
Healthy people vary in where their 'usual' fT4 sits within the range .. and 25% is fairly common.
Some healthy people would usually have 25% , while others would usually have 75% .. neither number is 'wrong' .. but the individuals 'set point' for fT4 is relatively narrow .. so 75% might be 'too high' for someone who 'usually' has 25% ... and 25% might be 'too low' for someone who 'usually' had 75%
If 25% was lower than what your daughters body usually had when healthy , then you would expect her TSH to rise to ask the thyroid to try to make some more T4... but since her TSH is at around 1 then these result show no obvious indications of a thyroid problem .
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
You can compare her levels to the 10 healthy people below whose fT4 / fT3 / TSH have been converted to % through range .
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
TSH is not a 'thyroid hormone' , it is just a message from the pituitary to the Thyroid Gland asking it to make more T4/T3 ( these are the Thyroid hormones )
When T4 goes too low , TSH rises.
When T4 goes too high , TSH lowers .. usually it's 'happy' about 1 ish.
The only time 'raised TSH indicating lower than usual T4 levels' doesn't apply is if the pituitary is not capable of making enough TSH for some reason ( this is called Central / Secondary Hypothyroidism ~ where the thyroid doesn't make enough T4 because it isn't being asked to.
(when T4 is too low and the thyroid is being asked to by high TSH , but cant manage to make enough, that is called Primary Hypothyroidism)
Thyroid bloods can also be misleading if tested at times of acute/ severe illness.
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Hi tattybogle,
Thank you for speedy response and assistance.
I am going to request another appointment with the Doctor to discuss further.
You have given me some understanding of what to ask now.
Thanks again.
Doctor probably won't be allowed to test fT3 ( the lab will usually say no even if GP asks for it ) ... in early hypothyroidism fT3 usually remains pretty good anyway .. it's the most important thyroid hormone , so the body protects a stable level of fT3 for as long as possible .
usually......in primary hypo , the fT4 goes low (usually because the thyroid is damaged by the immune system~ Autoimmune Hypo) .. the lower T4 triggers a rise in TSH .... which asks thyroid to increase T4 production .. if fT4 still remains too low, then the TSH goes higher .. and this asks the thyroid to make a larger ratio of T3 to T4 than usual to make sure the fT3 level stays good even if fT4 level is low.
you could ask GP to test B12 / Folate/ Ferritin / Vit D .. they might do those if your lucky
it's a good idea to get B12 / Vit D /Folate /Ferritin levels checked , if not done already .and post results here for advice .
Also let us know what symptoms she has .
Thank you so much for your feedback. I feel I understand it a bit more now. I have managed to get an appointment with the Doctor and will request further test to be done and post here for advice.
My daughters symptoms are;
Hair Loss, craves sugar, weight loss, feels faint/dizzy, hands get cold & finger nails beds can turn quite blue.
She also needs thyroid antibodies tested for autoimmune thyroid disease also called hashimoto’s
Thyroid peroxidase antibodies and Thyoglobulin antibodies
Hashimoto’s frequently starts with transient hyperthyroid results and symptoms before becoming increasingly hypothyroid
Plus testing for PCOS
(poly cystic ovaries)
Hair loss frequently low iron/ferritin
weight loss could also be gluten intolerance - request coeliac blood test
Gluten intolerance very common with thyroid disease
Regarding the level of TSH, the distribution of TSH in a healthy population is highly skewed towards the lower end of the reference range. In people with properly treated thyroid disease it is common for their TSH to be lower than that of a healthy person.
Many treated hypothyroid people feel best with a TSH that is 1 or less, but this is quite variable from patient to patient.
See this thread :
healthunlocked.com/thyroidu...
.
The Free T4 result is 25% of the way through the range. This is too low for the majority of people with hypothyroidism. A healthier level for us is usually somewhere around 60% - 80% of the way through the range, although, again, this can be quite variable.
But the active hormone is T3, and annoyingly doctors have decided they don't need to know this. Patients who test themselves and find out their Free T4 and Free T3 have found that Free T3 is the best indicator of "wellness".
.
Sadly, doctors think that hypothyroidism doesn't need to be treated until TSH is 10+, although if TSH is over the reference range, and the patient has symptoms and positive TPO antibodies then some doctors will treat then.
TSH is produced by the pituitary in the brain, not the thyroid. There is an assumption by doctors that everyone can produce sufficient TSH to stimulate their thyroid to produce enough T4 for the patient's needs but this isn't true. This problem of insufficient TSH production is called Central Hypothyroidism. Doctors think this is vanishingly rare, but having read this forum for 10 years I am sure they are wrong. It is very, very difficult to get a diagnosis and treatment for Central Hypothyroidism.
.
Edit : tattybogle thinks and writes much faster than me, so I was writing the above while she was zooming along with three times as much information. 
Medics are reluctant to acknowledge the importance of T3....and we suffer as a result!
It is the active thyroid hormone essential to every cell in the body. For good health it must be available in an adequate and constant supply
Furthermore, to become active it must reach the nuclei of the cells and attach to T3 receptors.
When the thyroid begins to struggle, in order to provide the body with essential T3 the body ramps up production of T3 to keep level as high as possible for as long as it can. It may eventually crash!
That "emergency" high FT3 level however doesn't seem to prevent symptoms.....you remain tired, overweight etc?
FT4 will be low and TSH will will be low because of the "emergency" level T3
TSH is not a reliable marker....it only reflects the overall level of hormones in the serum....not the level of each hormone.. It is a pituitary hormone
Your daughter's TSH is possibly being kept low by a raised" emergency" T3 level
Her miserably low FT4 along with low TSH indicates something is wrong....
that low FT4 would normally raise TSH!
Normally in health we need TSH to be close to 1....as your daughter's level is. But this can be a misleading reading....it only looks "good" because her FT3 has been ramped up.
Most people need their Free to be sitting somewhere approaching 75% through the reference range....with the caveat that we are all different!
Most people would be struggling with FT4 at 25% through ref range.
Both Frees should be a roughly similar percentage through their respective ref ranges
In order to have an accurate evaluation TSH, FT4 and FT3 need to be tested...I suspect her FT3 is raised considerably in comparison with her very low FT4.
Also important to test vit D, vitB12, folate and ferritin and thyroid antibodies TPO and Tg
If GP can't help private testing is available
thyroiduk.org/help-and-supp...
Sorry...this is a bit long winded but hopefully you get my drift!
Repeat thyroid test results
thyroid blood test results
Thyroid function test results
Understanding Thyroid Test Results 
thyroid function test results
