I have been on and off out of sorts for awhile now. I had blood tests done in July including for my thyroid, all within range. I looked at the results last night again for no real reason and noticed that my free T4 by many lab reference ranges is low.
My result was:
TSH 1.41 mu/L
Free T4 (thyroxine): 10.86 pmol/L
The reference ranges given are 0.35 - 3.5 for TSH, and 7.5 - 21.1 for thyroxine. However digging around online I find many trusts have a range of 12 - 22 or 10 - 20. Some have a range from 7 or 8 but this seems less common.
So I read a bit more and it seems normal TSH and low T4 can be indicative of secondary hypothyroidism. I look up symptoms and so many match me - sensitive to cold, headaches, tiredness, muscle and joint pain, low mood, hair loss etc. I don't have particularly dry skin or hair but otherwise so much is similar. I also have further risk factors by being female and a family history of pituitary disorders, my mother had some growth problem as a child with lots of time off school with painfully fast growth, early puberty etc.
I also have sore neck glands down into my collar bones and last time she saw me she said 'ooh I think you're unwell, you're very lumpy bumpy' but then when bloods were 'within range' that was it.
I have had thyroid tests before and TSH have always been similar.
July 2021 (as above):
TSH 1.41
T4 10.86
April 2021:
TSH 1.2
T4 11.5
August 2013:
TSH 1.84
T4 12
July 2009:
TSH 1. 2
T4 12
I'm 32 with two children. Anyone have any experience of this? Does it sound plausible? I feel like if I lived in another trust area I might be having further tests now.