Longstanding user of thyroxine. Underactive thyroid.

[Harper]

I have been on thyroxine for nearly 40 years. I am now experiencing problems with loose stools. It makes life difficult. Is this common? Does anyone have any answers please ? Thank you.

[SeasideSusie Remembering]

I've been taking Levo since 1975, I've never had this problem, quite the opposite! Even now I'm optimally medicated I still need help in the bowel department. You could have developed loose stools for another reason, it is said that we should check with our doctors if we have any change in our bowel habits.

[Judithdalston]

Could be hypothyroid, assume you have ruled out other causes? Your hypothyroid needs may well have changed over so many years, do you get blood tests for anything more than TSH? Your GPs might well be happy with a TSH anywhere within the range eg. 0.27-4.20, but as you go towards 3 and above you start getting hypothyroid symptoms: some get constipation, others loose stools. May be worth getting full thyroid TSH, FT4, FT3, total thyroxin, two autoimmune antibodies ( TPO and TgAb), plus folate, ferritin, b12 and vit D tested ...if your dr. won’t do them then consider private lab like Medichecks or Blue Horizon. You might need bit more levothyroxin or/ and vits/ mins. to get rid of your tricky symptom.

[Hidden]

Have you by any chance had a change in brand of medication ?

What brand are you using? My Morningside leaflet mentions diarrhoea as a possible side effect(Liothyronine ) though I don't know if it would be the same for their thyroxine.

[helvella Administrator Thyroid UK]

In my opinion, the most likely cause is that you are effectively over-dosed. (But remember none of us here is medically qualified.)

(Although the cause could be nothing to do with your thyroid hormone levels, I wouldn't know where to start in identifying other causes.)

Things which affect how much you absorb and/or how much you need:

Change of make of the thyroxine you are taking.

Change of when you take it, whether you take it near food or drink, and similar factors.

Any change in other medications, or supplements.

Significant changes to your diet.

Change in your weight.

Any other illness you suffer.

Significant changes in activity levels.

Changes in your levels of things like iron - perhaps you have always had low iron but now have adequate levels.

From where you are now, the first step is probably to get test results. Whether that is asking your surgery for your most recent results or getting re-tested. If they do not show you being over-dosed, time to think again. If they do show you being over-dosed, then simply reducing your dose a little might be sufficient.