Does having a cold, feeling run down affect thyroid blood test results?

[Crazy_CatLady]

Does anybody know if having a cold can affect thyroid blood test results? I've bought a test for T3, T4, TSH and antibodies. I was planning to take the blood tomorrow, but I have a bit of a cold. I don't want to waste the test by using it if the results could potentially be artificially skewed. Thanks 🙂

[SlowDragon Administrator]

Don't do it tomorrow, it needs to be processed by the weekend. Usual advice is to do Monday or Tuesday (Wednesday at a pinch)

Your CRP test would probably be elevated, not sure if anything else would

Are you testing vitamins too?

[Crazy_CatLady in reply to SlowDragon]

Thursday is usually fine with Medichecks, turnaround is one day, so I normally get the results the day after posting. But, I think I'll wait anyway, give my cold chance to go away

[radd]

Crazy_CatLady,

I don't know about a cold but the increased temps due to an immune system response can affect TFT's.

Thyroxine binding globulin (TBG) which stores and carries T4 in the blood, releases thyroxine with increased temps so as temps rise, T4 rises too. The hypothalamic-pituitary-adrenal (HPA) axis, the immune system, the central nervous systems, cortisol, and thyroid hormones are all involved in this process.

.

tiredthyroid.com/blog/2015/...

[humanbean]

I often feel a bit better on those rare occasions when I have a cold or other minor virus. I think it is because my temperature might make it to near normal, and when that happens I feel that my body works better. Normally my temperature is quite low even though I'm treating myself for hypothyroidism.

Whether my TFTs would be affected by an increase in body temperature, I haven't a clue.

[greygoose]

Your conversion could be affected, so the FT3 might be lower than normal. I would wait till you're over it, if I were you.

[Saggyuk in reply to greygoose]

Yes, my levels always take a fall when ill so normally wait for a week until after i'm better. I often feel better too in regards to my every day type issues - prob because immune system distracted but t3 levels still always low lol

[Crazy_CatLady]

Thanks for the replies, I think I'm best waiting until I'm over the cold, even though it's not too bad, no temperature. Better to get a more representative test result 🙂

[MrsRaven]

Early this year I was ill with a flu bug that left me with a bad sinus infection. The GP gave me antibiotics and strong steroid nasal drops - my head and eyes throbbed and it felt as though my eyes were going to fall out. As I recovered from the virus I got bad hypo symptoms and decided to get full bloods including RT3 done. My TSH was very suppressed, so were my FT3 and FT4 which were dragging on the bottom of the range. My doctor didnt have any advice, he kniws I self medicate on T3, except to up my T4 abd T3 and see what happened.

[Kitten44]

oh no, i too have a cold and yesterday I had a blood test. I waited 2 weeks for it, and it was the first time in 18 months that gp agreed to test me, so i was very keen to have it. Now I'm concerned that it may not show true results.