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Thyroid UK
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Cold sensitivity


this is my first post here. I am not from uk but i found information on this forum very useful. And i hope than some of you could answer my questions ^^

First here is my introduction. I have Hashimotos, had it diagnosed more than 15 years ago, in high school, and treat it with L thyroxine since then. However, in recent years i am feeling much worse(tired, sleepy, brain fog, some allergy-like sinusitis) than i used to, and that motivated me to look into this disease and what is written on it in the internet. I found out eating gluten can be harmful for me, i found out about autoimmune paleo protocol(aip), about vitamins i probably need to supplement and other stuff i didn't even think about before. So 6 monthes ago i started following aip hoping it would help my health problems. So far I'm not even sure I'm doing it right and if there are any improvements due to this diet. I lost some weight though and my family says i look more healthy lol so i keep eating like that, trying not to cheat too often.

Anyway, my question is something else. You see, i am really very sensitive to cold. When other people around me would sleep without any blankets i need 2 to feel comfortable. I hate air conditioning and would rather sleep/work in heat etc. I think i was like that since forever, but something weird happened to me this weekend. We went abroad with my friends for 3 days 2 nights and i forgot to take my L-thyroxine with me. So i missed taking it 2 mornings and i don't know if it's just coincidence, but i didn't feel cold in the mornings as i used to before. Then i came back home, and it felt really hot sleeping the way i used to. But in the morning i took finally L thyroxine pill and then went back to sleep. And as i woke up again it felt so cold again. So now i have suspicion it may be connected to the pause in medication? What do you think? What experience do you have on this matter? Thank you in advance :)

10 Replies

It would be really useful if you have copies of your thyroid blood test results with the reference intervals (numbers in brackets). This would give an idea of your overall hormone levels.

Feeling cold is usually a symptom of too little thyroid hormone, but this doesn't fit in with you being better when you stopped the levothyroxine.

I wonder if you picked up a bug on holiday or caught a cold. This might be mild and raise your temperature a little. I suggest you give it a week or two and then try stopping your levothyroxine for a few days to see if it happens again.

In the meantime post your blood test results here, or if you don't have them put in a request to your doctor for a copy.

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Thank you for your reply, jimh111.

This is a good idea to try this again few weeks later. The circumstances this time were too different from the usual ones, for sure. Might have been just coincidence.

Here I have thyroid blood test results from 18.02.2016:

some things translated from Estonian, so I'm not sure if the terms are correct

Serum aspartate aminotransferase (?)

21 (result) U/L (units) <32.0 (reference)

Serum alanine aminotransferase(?)

13 U/L 0.0 - 33.0

C-reactive protein in the serum(?)

0.13 mg/L 0.0 - 9.0


2.451 mIU/L 0.4 - 4.0


13.40 pmol/L 11.5 - 22.7


75.9 kU/l <60.0

Vitamiin D, 25-OH (Q)

63.6 nmol/L >75.0 optimal



and just basic blood test:

18.02.2016 NEU 39.7 % 40.0 - 80.0

18.02.2016 LYM 47.2 % 20.0 - 45.0

18.02.2016 MONO 8.20 % 1.0 - 11.0

18.02.2016 EOS 3.80 % 1.0 - 5.0

18.02.2016 BASO 1.1 % <1.0

18.02.2016 RBC 4.66 E12/L 4.0 - 5.1

18.02.2016 HGB 137 g/L 118.0 - 150.0

18.02.2016 MCV 88.00 fl 82.0 - 99.0

18.02.2016 MCH 29.4 pg 28.0 - 36.0

18.02.2016 MCHC 334 g/L 310.0 - 370.0

18.02.2016 RDW 12.4 %CV 10.0 - 15.5

18.02.2016 PLT 262 E9/L 150.0 - 450.0

18.02.2016 MPV 10.5 fl 5.0 - 12.0

18.02.2016 Trombokrit 0.270 % 0.1 - 1.0

18.02.2016 PDW 13.1 % 12.0 - 20.0

18.02.2016 WBC 5.25 E9/L 4.1 - 9.4

18.02.2016 NEU 2.1 10*9/L 1.5 - 6.7

18.02.2016 LYM 2.5 10*9/L 1.3 - 3.6

18.02.2016 MONO 0.4 10*9/L 0.2 - 0.8

18.02.2016 EOS 0.2 10*9/L 0.03 - 0.44

18.02.2016 BASO 0.1 10*9/L <0.1

18.02.2016 Glükoos paastuplasmas 5.1 mmol/L 4.1 - 6.1

18.02.2016 Hematokrit (Q) 41.0 % 37.0 - 47.0

All this time I have slightly elevated BASO results 1.1 - 1.2 (had done basic blood test more times since thyroid blood test), don't know what it means and if it's connected with thyroid issues.

Tests show low vitamin D results but since then I changed my lifestyle to AIP and am taking different vitamins - D, Mg, B, Fish Oil and probiotics. I guess I need to ask for a new tests now, but here it means I will be able to get them maybe in next 2 months.

Interesting thing, these tests were the reason I found this forum actually, because I was googling how and when the tests should be taken :)


As well as having your thyroid results if you also have results for vitamin D, vitamin B12, ferritin and folate post those.

If you haven't been tested for those it's worth doing so.

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Thank you for your reply, bluebug.

I think I only have result for vitamin D and it's outdated. I will get tested for all these as soon as I can.



Welcome to our forum and sorry to hear you are having health issues.

Thyroid hormone is responsible for our metabolism which dictates the rate at which our body's many processes function and converts food into energy. Heat is a byproduct of metabolism and as low thyroid hormone slows metabolism, so the process of generating heat is compromised or lost.

Being constantly cold & slow is so miserable and the worst I felt was still having that inner coldness when even laying in a hot bath. Being warmer was one of things I noticed most and still so appreciate, with optimal thyroid hormone replacement, but I still get cold knees when I am tired and hate air conditioning too.

Some people who are either under-replaced or intolerant of their meds actually feel better for a few days if meds are left off. However, this improvement is obviously short lived as missing hormones need replacing. Post any blood test results complete with ranges (numbers in brackets) for members to comment.

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Thank you for your reply, radd.

I posted my old results above. Interesting, last year I had to increase my dose (it used to be 50 mcg), and now I am altering 50 and 75 mcg, as my doctor told me. Maybe I could be under-replaced or intolerant. How is it possible to check? How did you reach optimal thyroid hormone replacement?

Also to take 75 mcg i break pill in half. Is it safe to take the other half after 2 days? Also I wonder when is best time to take pills. I used to take them right when I get up and then I had to wait at least 20 min before eating. Now I sometimes wake up earlier in the morning and then take the medication and get back to sleep. So when I get up I can eat without waiting. Is it so important to take pills exactly 30-60 min before breakfast?


I think you're underreplaced, judging by your low t4 and tsh.

It is important to take your meds away from anything you might eat or drink that isn't water, including supplements. I set my alarm for a few hours before I need to get up, take my meds with water and go back to sleep. The exact amount of time isn't that important, but if you're underreplaced and you want to get the best out of your meds it would be an easy way to see if you could make an improvement. I think 30mins is a minimum gap, and if I were you I'd try taking them at least an hour before food.

I wouldn't worry about breaking the tablet in half. Keep your meds away from strong light or extreme temps, but otherwise there shouldn't be an issue.


I suspect you are undermedicated. Most people on levothyroxine need an fT4 around 18. Patients are usually on 100 - 150 mcg levothyroxine. I wouldn't worry about when to take levothyroxine, there is less absorption if you take it close to food but as long as you are reasonably consistent there shouldn't be a problem. Twenty minutes (or longer) before breakfast should be OK for you - it may not be OK for others. You can take the levothyroxine before bedtime if you find that easier.

Tell your doctor you feel cold and ask for an increase - maybe 100 mcg daily.

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Thank you very much


The others have pointed out you are under medicated.

You also have a too low vitamin D level, and while you haven't posted vitamin B12, folate and ferritin it is very likely one or more of them will not be optimal.

As the vitamins and minerals are needed to help your thyroid you need to get your levo dose increased plus find out what your vitamin and mineral levels are.

Post when you get new results so people can advise you on how to get the vitamin and mineral levels optimal not just good.

BTW one common reason liver enzymes are low is due to insufficient nutrition.

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