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Thyroid UK
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Hypothyroidism and Hypoglycemia

Hello Everyone

I had a Synthyroid/Cytomel change about 5 weeks ago and I've been experiencing hypoglycemic issues ever since and I'm not sure if I'm having sugar issues now or if it has something to do with my medication change or from my recent shingles outbreak although I'm not sure how shingles could bring on sugar issues. Let me explain my issue.

I've been on a mission to shed the 35 pounds I've gained over the past 13 months after my thyroidectomy and one of the ways has been to cut back on my carbs I have a small amount of carbs at dinner time and this is when my hypoglycemia symptoms seem to happen to me (after) 1-2 hours of eating my husband and I go out for a 3 mile walk and within 30 minutes my sugar drops It feels like I'm drunk and I start to stumble, feel breathless, stutter my words and shake if I eat a few mints that I carry my sugar comes back up it takes about 10 minutes for it to kick in.

This hyhypoglycemia things only happen if I eat dinner with potatoes, pasta and sweet potatoes although it happens even if I don't consume these items just not as often as with the items above. I experimented several times and it's carb induced for sure, I'm not sure why now.

Could this be happening because of my recent Synthyroid/Cytomel change or Valtrex (meds) from shingles. Im not scheduled to get a blood test until Feb 8th for thyroid level.


11 Replies

This paper review might be worth a read:

Indian J Endocrinol Metab. 2014 Jan-Feb; 18(1): 1–3.

doi: 10.4103/2230-8210.126517

PMCID: PMC3968713

The hypoglycemic side of hypothyroidism

Sanjay Kalra, Ambika Gopalakrishnan Unnikrishnan, and Rakesh Sahay

1 like


This is the link ijem.in/article.asp?issn=22...


I've not had thyroid meds cause hypoglycemia, but am a Type 1 diabetic & have too much experience with hypoglycemia. Sorry it is a terrible feeling. Basically, your pancreas is producing too much insulin in response to fast acting catbs, so it's great you've cut down carbs. Before your walk, eat some protein. Protein helps keep glucose levels stable. About 50% of protein does turn to glucose, but at a slow rate. Also good to eat a little protein after you treat with the mints. Please keep an eye on your levels with a glucose meter. You may be experiencing highs before the lows. Normal blood glucose is in the low's 80's & not more than low 120's shortly after eating that quickly comes down to the 80's. You should a request an A1c from your doctor. A1c measures your glucose over a 3 month period.


G2G2, I can and always have gone for a 2 hour walk before I eat in the morning and my sugar never ever drops only seems to happen at nighttime after I eat dinner and for years my sugar has always tested (70). I'm scheduled to do a sugar test next week. I'm also having issues with severe dry eye syndrome,Diagnoised years ago recently increased 10 folds and I wonder if the dry eyes and sugar issues are connect along with my thyroid levels and I wondering if I'm still hypo after recent med change?

Will my health ever get better "sigh"


Yes, it's after eating causing the glucose drop. It's called reactive hypoglycemia. Hope your health gets better. Know how frustrating it is.


Is this a medication thing or does it happen to everyone that has no Thyroid? I'm confused why now and not over the past 13 months.


Afraid I don't know if it's caused by medication. Personally, I've not heard of it for people without a thyroid. Glad you're getting a glucose tolerance test. Reactive hypoglycemia is different than hypoglycemia, which can occur at any time. Please do ask your doctor for an A1c test. Not to frighten you, but reactive hypoglycemia can be a precursor to diabetes.


Canyouhearthat, I have also had hypoglycemia issues with my hypothyroid. The worst I've had was when I tried a low carb diet. This kid of diet is good for some hypos, but very bad for others.

I started to eat a piece of bread most mornings, and rice or pasta a couple of times a week and it reduced a lot.

Have you considered that it's the walk that's the problem? It sounds like you always have these issues when you exercise, so maybe you've started exercising too soon.

It would be worth checking if your thyroid hormone levels are optimal. Post your latest results in a new post, and members will comment. If you've got ferritin, folate, vitamin D and vitamin B12 these are also worth looking at.


Silver Avocado, What do you mean exercise too soon? I've always follow this exercise routine for years and I haven't had these hypoglycemic issues until recently after my Synthyroid/Cytomel change, I won't know if my levels are off until I test next week and will make separate post with those results.


Apologies, I thought you'd had a thyroidectomy 13 months ago.


Lol, yes I had my thyroidectomy 13 months ago


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