HI, I understand that the measurement range for TSH (thyroid stimulating hormone) is 0.4 to 4.0ml. I have had 22 readings over the last 12 years, and they have all been well below 0.4. In fact, they have been <0.05 and the medical printout says "outside reference range".
Within the same period my free T4 readings have always been within the acceptable range (9.0 to 25.0).
I suffer from a range of symptoms including fatigue, brain fog and lack of enthusiasm.
Could anyone provide any insight into these readings. My GP does not understand them.
Written by
BarbaraC
To view profiles and participate in discussions please or .
TSH 0.05 with FT4 and FT3 within normal range indicates subclinical hyperthyroidism. What was your last FT4 result (please include the range)? If you've had ferritin, vitamin D, B12 and folate tested please also include the results and ranges.
T4 15.7 is unequivocally euthyroid so although TSH is low I don't think your symptoms are likely to be thyroidal. Ask your GP to test ferritin, vitamin D, B12 and folate. Low/deficient levels can cause fatigue, brain fog and low mood.
I am not a medical professional and this information is not intended to be a substitute for medical guidance from your own doctor. Please check with your personal physician before applying any of these suggestions.
With under the range TSH and T4 (I'm assuming it is Free T4) in the lower half of the range you may have secondary or central hypothyroidism.
This is where your Free T3 level is vital for getting an accurate diagnosis.
If it is high then you might have subclinical hyperthyroidism as Clutter said.
If it is low then you may have secondary hypothyroidism as I suggested.
If it is reasonable then you are euthyroid (i.e. your thyroid is normal) and your symptoms may be caused by something else e.g. low minerals and vitamins.
Since your doctor is unlikely to help you (he hasn't done for 12 years so why would he change now?) you have a couple of options.
1) Change your GP - see a different GP in the same practice, or change practice altogether. Then see if one of them would agree to test your Free T3.
2) Stay put, pay for your own private testing and ask us for advice on the results. You can get the basics done - thyroid function testing, antibody testing, and the essential minerals and vitamins - for £99 from Blue Horizon.
Look for the "Thyroid Check Plus Eleven". The Collection method you need to order is "Microtainer (collect at home)".
What happens :
1) You make the order. A kit gets sent to you through the post. It contains full instructions, mini test tubes, lancets to prick your fingers for a blood sample.
2) On the day when you are ready to do the test, do the blood collection around 7am - 8am. (Thyroid testing should be done first thing in the morning.) Don't eat in the morning before the blood collection, and don't drink anything except water. Don't be dehydrated either.
3) Package up the bits you need to send back to BH and take it to the post office the same day you do the collection. Ask for "Special Delivery Guaranteed by 1pm".
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.
Getting to the top of FT4 range with suppressed TSH 
TSH values for the older person
What affects the TSH reading? 
TSH levels all over the place!
Advice please Dr wants TSH within range.
