blood test interpretation FT3 in bottom half of range

[mmthyroid]

My 18 year old daughter had blood tests that included TSH, FT4 and FT3. It was part of a regular checkup. Her results seem off to me, but the only issue she has is long, painful periods. Any thoughts on whether we should investigate further. Her FT3 is 4.9, range 3.5-7.7

FT4 is 14.2, range is 12-22

TSH is 1.66, range is .27-4.2

I know the FT3 is low. Any thoughts on the others.

[SeasideSusie Remembering]

mmthyroid

I know the FT3 is low. Any thoughts on the others.

TSH is where it should be. In a normal healthy person TSH is usually no more than 2, often around 1.

Her FT3 is 33% through range, her FT4 is 22% through range.

The problem is, none of us are tested for a baseline when healthy, so we don't know our "normal" levels. If she has no hypothyroid symptoms then it doesn't seem that she has a thyroid problem.

[SlowDragon Administrator]

Heavy periods frequently lead to low iron and ferritin

She needs Folate, B12 and vitamin D tested too

[jimh111]

Her results are fine. If she doesn’t have other obvious symptoms I wouldn’t worry. Pain can be tiring and this may cause her TSH to lower a little leading to lower fT3 and fT4. Obvious they should check out her female hormones if this hasn’t been done.

[SeasideSusie Remembering]

DippyDame

For good health both should be close to75% through their respective ranges

TSH at 1.66 is too high it should be 1 or even below

That's for someone who is on levothyroxine.

A normal healthy person will generally have a TSH no more than 2, often around 1, with FT4 around mid-range-ish, but no-one knows where their own normal levels in health are as we're not tested for a baseline.

[DippyDame in reply to SeasideSusie]

Ouch! Bad mistake....basic error. Thank you for correction.I'll delete my reply.

[Nanaedake]

I would definitely get vitamin levels and iron tested. Just because she doesn't have a thyroid problem doesn't mean everything is alright. Could be low iron like someone else suggested. If periods are painful there might be another issue that needs ruling out. Sometimes our thyroid under performs a little due to deficiencies or inflammation.

[jrbarnes]

In regards to long painful periods I would investigate possible endometriosis or fibroids, however I don't think fibroids are as common in teens as endometriosis is. I had pain linked to my period in my early 30s and it was due to a fibroid. I had another friend who suffered from period pain starting in her teens and it was due to endometriosis.