Thyroid UK
84,083 members99,057 posts

Hypothyroid for about 15 years, pregnant and have just found out I'm Reactive Hypoglycemic. Any advice much appreciated!

I'm 43 years of age and 26 weeks pregnant. Due to my age there is an increased risk of gestational diabetes, so yesterday I had a glucose test. I have been given my results quickly and it seems that my blood sugar level was higher after fasting for 12 hours than it was 2 hours after a glucose drink, it turns out this is called Reactive Hypoglycemia.

For the last hour or so I've been doing lots of searching online to find out as much as I can. It seems that it can be related to being Hypothyroid, but I'm not really sure why or how. It also appears that a lot of people have to drastically change their diet, but these people aren't necessary Hypothyroid too.

So I'm looking for advice from any of you that are both Hypothyroid and Reactive Hypoglycemic.

I've been diagnosed Hypothyroid for about 15 years (although I am certain I was undiagnosed for a good 10 years before that), I'm currently on 200mg Thyroxine per day (recently increased from 175mg due to pregnancy). I'm also taking 200mg of iron 3 times a day as prescribed by my GP. I also take a Calcium/Magnesium/Zinc supplement twice a day and fish oil, vitamin D and folic acid once a day.

I have found it hard to sleep for as long as I can remember, I currently feel very tired through the day and often resort to napping/trying to nap. Often I can't sleep as I am just too overtired (this is something my partner finds hard to understand). With an active 2 year old and a baby due in May, I'm desperate to feel better and I'm now wondering if the Hypoglycemia is the root of the problem.

Any help or advice is very much appreciated.


9 Replies

Hi Congratulations! As you say diabetes etc. is more common in pregnancy, often OK once had the baby. it often improves. hypoglycemic and diabetes.i had it for many years before I became diabetic, I see a brilliant endo so had the advice. I am Hypo. If worried ask to see an endo. however, if you eat, carbohydrates when you feel that you are hungry etc., that is normally all that is considered necessary. You will notice , when you need to do this without any difficulty.You should try and have some, a little carbohyrdrate every 2 hours in the day. Just a biscuit sometimes should do.

Best wishes,



Hi, I am hypothyroid and was diagnosed with gestational diabetes while pregnant 9 years ago. I didn't have my thyroxine increased while pregnant though. I take 150mcg a day. Memorys a bit fuzzy but I just seem to remember going to the hospital for check ups nearly every week to have blood tests and see the diabetic doctor. I had to keep a food diary and up my exercise!!! (walking). I had extra scans to check on baby and had a cesarean a 38 weeks as baby was getting large due to the diabetes. She was 9lb 2oz..She is now a lovely 9 year old girl Phoebe. I have not diabetes and am checked anually for it. I know my situation is little different but I hope this helps put your mind at rest. Oh i had to do finger prick blood test a few times a day and keep a record of that's all coming back to me And I had been underactive for 10 years ( or more undiagnosed) previous to the pregnancy. I recieved great care throughout and also had another child previous who I had to get to school every morning even though I really really was shattered and didn't want to get out of bed.!!!!

Take care, put yourself first when you can and take any help you can get.

Louise x


Low carb diet.

Personally I do a low Glycaemic Load diet, but all the low carb methods seem to work, take your pick.

Been 100% symptom free for over 3 years this way. Before I was flaking out every day, life was like I was on some sort of roller-coaster ride, even during the night I was waking in a panic as low blood glucose triggered an adrenaline rush! There is a weight loss benefit of it too of course, and I admit it is a bit of a drag, but like everything else they claim to deal with, Endocrinologists in this country don't have any answer for it, and think that pumping people full of carbs as some sort of answer to this (and even full on type II diabetes too), when it is the CAUSE, and low carb gets it under control straight away for most people.


Hi, congratulations!!

I just wanted to say that if hypothyroid and pregnant, your thyroxine dose should be increased slightly. Many docs are not aware of this. Diabetes or not, you have an increased risk of large babies due to the baby making thyroxine for you (I had two 10+ pounders). I am not an expert at all in reactive hypoglycaemia, but I reckon I'd see a nutritionist for advice. Oh, and caution with the iron tablets. If you're at all constipated, please consider Solgar gentle iron instead as it could help prevent post- birth complications. I used this to get my Hb up to normal after birth and avoid a transfusion, so I know it works well (after being very sceptical about this advice from my rather alternative midwife).

I agree that looking after a toddler and being pregnant is exhausting! I hope you feel better as it progresses.



That's very interesting - I had a fasting glucose test recently & although the level was within range it was very very close to the top. Whereas a previous one done two hours after eating was quite low. I'm not diabetic but both my parent were (Mum was insulin dependent and very bad with it)

Flo B


Hi girls. Can't add directly to this, but what you describe about blood sugar rings bells for me too. (definitely not the pregnancy part though)

Wonder if there isn't some underlying abnormality involving blood sugar issues that predisposes to or is linked with hypothyroidism too?

Its worth saying that it's very important (from what I've read) to ensure that you are not hypothyroid during pregnancy - especially not during a critical period around the start of the third quarter where rapid development of the thyroid and other metabolic regulatory systems is taking place.

The foetus relies on the availability of a generous supply of hormone from the mother to support these processes during this period.

I can't quite remember the details, but it creates a high risk that the baby will be born with a tendency to hypothyroidism (and potentially other issues) - possibly because some critical enzyme processes fail to develop properly. There's papers out there on the topic. (i might have a reference, but am not sure)

I'd love to hear of any insight you may have on the blood sugar/hypothyroidism link.

Hypothyroidism runs in one strand of my mother's family, and I was born very premature.

I've had some sort of problem with control of blood sugar levels since I was a kid, and eventually ran into the classic secondary hypothyroidism with thyroid auto immune disease (producing enough hormone, but not converting and using it properly) in my late 20s.

This despite repeated attempts to get a doctor to listen/take account of the symptoms over many years (they clearly pointed to hypothyroidism) was never diagnosed (the usual 'blood test say normal... beep' stuff) - replacement only started after a thyroidectomy for thyroid cancer.

It's always been the case that if I exercised without having recently eaten carbohydrates that I would run into a really severe problem with low blood sugar - with nausea, trembling, no energy, weakness (maybe even collapse) and so on.

I discovered while training and competing in sports in addition that the traditional carb loading procedure used by many before marathon/endurance type events left me feeling really ill and weak. (that's where you eat protein/no carbs for a few days, and then eat excess carbs in the day or two before an event - the theory is that the body stashes away extra glycogen for increased endurance)

It's also become clear that i start to feel very unwell after a couple of days on a low carb Atkins type diet, but that equally a high carb diet causes bloating and nausea - I find I need to manage my carb intake fairly carefully.

Sugar leaves me feeling very unwell, and upsets my already unstable blood pressure - which seems to be the result of cycling adrenal hormone levels. Which don't seem to be the result of stress.

It's possible that the above is by now all mixed up with some food sensitivities - I tend to minimise my intake of stuff like wheat, bread, milk, sugar and so on.

While ill before the thyroidectomy I had a couple of supposedly thorough work ups for the various endocrine conditions (Cushing, Addisons, suspect adrenal tumour etc etc), and was tested for diabetes etc. All negative.

I explained the blood sugar issue to the consultant, but for whatever reason it didn't seem to ring any bells for him....



I used to have problems with reactive hypoglycemia at university to the point that I would pass out. At that time I had a TSH just over 2 and was on just thyroxine. After finishing uni I decided to get to the bottom of things and switched to a combination of T4 plus 10ug T3 and maintained my TSH around 0.5 and haven't really had problems with it since - about 12 years now.


Thanks all for your comments and input. This subject sounds like it's a bit of a minefield and what works for one well may not work for another. I haven't yet changed anything about my diet, but today I have ensured that I have something to eat every hour or so whether it be a proper meal or just a biscuit or fruit. I've not felt too bad to be honest.

I always wake in the night, more often than not 2 or 3 times sometimes more, sometime around 2-4am I'll often be awake for one and a half to two hours. Usually I'll wait a while before getting something to eat (in the hope that I'll drift back to sleep), but from tonight I'll get something to eat straight away on waking and hope that that sorts me out more quickly.

Thanks again for your comments, any other insights are most welcome.


Have you checked to see if you have Adrenal Fatigue? Most do and sadly lack of sleep is a main symptom. I wish you much luck with your health and the baby. I recommend you check out for information on adrenal fatigue...also Dr. Wilson's book which is "Adrenal Fatigue, 21st Century Disease" on Amazon.


You may also like...