'Wall of fatigue', sudden extreme tirdness

Hello, I've just joined, I suffer from from sudden extreme tiredness like a wall of fatigue. I suddenly feel a little light headed, then I know I need to lie down. Once I'm in bed I can sleep for hours! Usually during the day. I sleep fine at night so don't know why this happens. Does anyone else have anything similar? I was diagnosed with underactive thyroid (Hypothyroidism) a few years ago, but not sure it's connected. Many thanks x

30 Replies

  • Your symptoms sound to me like hypothyroidism. Have you had a recent blood test for your thyroid hormones? What dose of levothyroxine are you taking? Have you had B12, Vit D, iron, ferritin and folate tested recently?

  • Yes I have Hypothyroidism, I've had it for some years now. I have a blood test scheduled next week so ill ask if they can do the items you have suggested. Could that be causing the Sudden Fatigue?? It's so debilitating, and afterwards I feel embarrassed that I just have to stop what I'm doing and sit down. I take 25mcg and have done for a few years.

  • Fatigue is a clinical symptom. My God, you are only taking 25mcg Levo.

    I am shocked that you've been taking it for years, no wonder you are having severe symptoms.

    Some advice re tests. You must have the earliest possible appointment for your 'fasting' blood test. Also allow about 24 hours between your last dose of levo and the test and take it afterwards. If your appointment is not at the earliest make another one and also ask for B12, Vit D, iron, ferritin and folate to be checked too.

    Get a print-out of your results and post them all with the ranges on a new question.

    People used to get prescribed, before the blood tests were brought in, doses of between 200 and 400mcg of natural dessicated thyroid hormones.

    A doctor who used to treat patients by clinical symptoms and not the TSH said and wrote to a newspaper to say that nowadays we were undiagnosed due to the 'rules' and that doses were far too low. Yours is a starting dose.

  • Many, many thanks, I will make my appointment earlier. Do I need to ask in advance for additional tests I.e. for B12, because I'm only seeing a practice nurse for the blood to be taken on the day?

  • I don't know if the nurse can do tests that you ask, so I'd phone the surgery on Monday and speak to nurse and ask what the procedure is for the surgery re tests. Tell her you'd like extra tests as you've been feeling rough and want thorough thyroid hormone tests as you've taken advice from the NHS Choices Thyroiduk.org.uk. She then might speak to the GP who might agree. I hope so. I've put the tests you should have on another response.

  • Thank you for all your fantastic advice, it's like a breath of fresh air! I will certainly post my results when I get them. Thank you again

  • Bear in mind I'm not medically qualified just have had experience of undiagnosed/unmedication hypo. :)

  • Typical symptom of hypothyroid.

  • I'm only in my 40's. Any advice on what foods to eat or avoid would be very helpful

  • Avarina, get your blood tests sorted out first before changing any foods etc. It's hormones you need. Tell the GP you would like your Free T4 and Free T3 checked at the same time as you've not had these very important tests before which you need. Your GP is being negligent in giving you such a small dose.

    The most important thyroid hormone in our body is T3 the only active hormone, and we have billions of receptor cells that need it, our brain and heart in particular. Levothyroxine is T4 and it's job is to convert to T3. If we don't have enough levo we wont have sufficient T3 which provides our normal energy.

    We should know our Free T3 and if doctor wont do so you can get a private one from a recommended lab. This is from TUK:

    FT3 = FREE T3

    T4 converts to T3 and is the only thyroid hormone actually used by the body's cells.

    The approx. reference range for Free T3 is 4 to 8.3

    We at Thyroid UK believe that you need to know your Free T3 level too because this will often show low if you are not converting, and high if you have blocked receptor cells. Even if you are converting, the body needs the extra T3 that a normal thyroid produces. There has been some research to show that people feel better on a mixture of Thyroxine (T4) and Triiodothyronine (T3). Effects of Thyroxine as Compared with Thyroxine plus Triiodothyronine in patients with hypothyroidism – The New England Journal of Medicine Feb.11, 99 Vol. 340. (Click here for this article).

    With all of these tests, your results could be anywhere within the range and you would be classed as "normal". If you are at the very edge of the range, either at the bottom or at the top, you could be classed as "borderline". Neither you nor your doctor truly knows what your normal is, if you did not have a blood test done before you became ill. There are also particular reasons why the blood tests remain in the normal range. If you are not converting from T4 to T3 or if your cells are not taking up the T3 normally, your T4 levels and your TSH levels will still show as normal.

    The Broda Barnes Foundation tell us "Dr Barnes found that the primary reason for the inaccuracy of the blood tests for thyroid function is that the thyroid hormones are not utilized in the blood, but are utilized intracellularly. Therefore a patient can have enough thyroid hormones circulating in the blood to give a "normal" reading, but if the hormones are not getting into the cells, the patient will be hypothyroid.


  • I'm going to make an appointment with a Dr to check What blood tests are being done (as I'm not entirely sure) Dr just said thyroid test. Plus also ask for the additional ones you have suggested. I'm so glad I found this forum.

  • It is ridiculous that you are on such a small dose.No wonder you are feeling ad you are.

    Do not be put off by being told your results are normal.Get them with the ranges and post for advice.

  • You shouldn't have to go in for another appointment to get the tests authorized. Can you speak with the nurese?

  • The least they do is the TSH and if you're anywhere in the 'range' believe that the dose of levo is s sufficient. In fact the TSH is from the pituitary gland not the thyroid gland. The next combo is TSH and T4 and again that wont tell you what your T3 is. They seem to be unaware what the purpose of T3 is in our body and it is the only Active Hormone.

  • Gosh, yes - I remember it well. I was diagnosed with chronic fatigue syndrome 10yrs ago. Hit that wall many times. In addition, I often lost all my energy - as if someone had taken a plug out of my feet and it all drained away. Very sudden. Could literally be left standing - with no energy to get anywhere. Only been treated for hypothyroid for 18months since a hemithyroidectomy, but thankfully all that has improved. Still feel more tired than I think I should - but no longer hit the wall.

  • Thank you all so much for responding, it's really giving me confidence to seek answers and great to not feel like I'm on my own with this.

  • Avarina, try to educate yourself. In the long run that is what will improve your health with this condition.

  • Many thanks for the video. I watched it for the first 6/7mins but find it so difficult to concentrate and take in information. I'm feeling so tired mentally as well as physically all the time. I will watch it in chunks, I'm trying to understand all the jargon, I wish there was a dummies version!

  • LOL, I'm sure you are no dummy. He does talk fast. I would take some notes because he really knows what he is talking about. He taught anatomy for 8 years and has many other videos on You Tube. The one on neuropathy is also full of information. You'll see how our body is reacting as it should even your brain fog. When you haven't enough thyroid, your body determines where it is needed most and probably robs Peter to pay Paul. Your adrenals will tamp down your thyroid if you don't have enough stored energy. It may have to use adrenaline to keep you going and that makes for some symptoms. You need to get the nutrients that may be lacking if you have been ill for a while. You might try taking apple cider vinegar before lunch and dinner to help. You could also be low in B12 and folate. Vitamin D is important for your immune system to function and most of us don't get enough sun exposure. There are many corrections you can work on.

    I'm sorry to add so much on top of all the other advice but you have been neglected for a long time.

  • Hi Avarina, I know that wall well but its been a lot better since my Levo was upped from 50 to 75. Still occurs (about once a month) but a lot easier to manage (although unpredictable). Good luck with your bloods. Joining this forum will provide lots of information and support. Its been a godsend. Hope things improve for you.

  • Hi Avarina,

    Perhaps you're undermedicated?

    Before medicating with NDT & T3, I had to sleep at 4pm every afternoon.

    If I undermedicate, have an upset stomach, or take anything that interferes with the meds, etc, the extreme energy drop returns.

    I use this as a barometer for how much to take. Usually the equivalent of 200mcgs of T4 as 2 grains of NDT & 25mcg of T3 is right for me to remain alert until the evening.


  • What kinds of things can interfere with the Levo uptake?

  • I've seen some lists on here, but only paid attention to things I consume.

    Any food, too soon after medicating. Also supplements such as iron, vitamin D, & HRT Caffeine affects absorption. For a while, I took HRT, iron & D at the same time. This probably reduced the efficacy of all of them considerably, so now I make sure to leave a good gap between NDT & T3, & anything but filtered water.

    I stick to restrictive eating times, so take my thyroid meds on waking, or when I wake up in the night. Most days, I don't eat till at least 11am, sometimes 12, then stop eating before 6. I

    eat a grapefrut every day, which slows down the rate of T3 absorption,

    but not the bio-availability to cells, ie, it doesn't reduce the dose,

    just makes it last longer.


  • That's really interesting, because sometimes I accidentally run out and have to wait a few days for a new prescription. After a few days on nothing I feel good and have actual energy.

  • This can happen if your blood sugar rises due to eating sugary foods, worth having a look at your diet throughout the day. This happens to me so the obvious answer is to avoid sugar in any form.

  • All your advice is fantastic! It's giving me lots to consider.

    Can I just double check.... the tests I need to ask for are:

    B12, Vit D, iron, ferritin and folate

    Free T3

    Free T4

    Fasting blood (is that what it's called?)

    Have I missed any?

  • You need the TSH done as well as the Free T3 and Free T4. The rest of the list is fine.

    Be aware that asking for tests is a good idea, but doctors won't always agree to do them, and often it is the lab that refuses. But if you don't ask, you definitely won't get!

    Fasting blood = get the blood taken first thing in the morning before eating and don't drink anything other than water (which you should drink freely).

    Assuming you usually take your levo in the morning, delay taking it until after the blood is taken.

    If you usually take your levo at night, don't take it the night before the blood test. Instead take the missing dose immediately after the blood draw, and then take it at night as usual.

  • Thank you for your help I'm going to call them now to see what they say :)

  • Ok, I rang Drs surgery today and reception said they are testing me for the following:

    Full blood count

    Bio clean (think that's what she said)

    Sugar glucose


    Liver & Kidney

    So I asked for B12, Vit D, iron, Ferretin, Folate, Free T3, Free T4 to be added

    She said iron, ferreting and folate are included in full blood count, but would add the others. Going on Wednesday so I will post my results when I get them. Probably next week.

  • Hello, I have just posted a very similar experience. I have exactly the same, had to stop work and go to sleep for 3 hours today! Often I get this symptom following a meal.

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