I am bit confused, as I see that most of people on this forum don’t rely on tsh alone, but my question is why? Isn’t tsh the best indicator of how much our body actually needs as the ranges can be so wide? My thing is that I don’t have thyroid and was feeling well on 125, 137 and 150 tyrosint but my results were- on 125 tsh was mostly around 2.5 and came up to 4.40 (I had broken leg at the time that could have caused the increase) and then when moved to 150 my tsh came down to 0.06. My doctor thinks I am over replacing and moved me down to 137 but my tsh is still at 0.07 (range 0.35-4.5). My FT3 and FT4 are at the middle and top of the ranges. I don’t know if because of that increase I have now plenty and steady inflow of the hormone, which caused my consistently low TSH or what? I heard that tsh suppression can cause some misbalance in the brain and cause conversion problems in the long run. Please advise! Thank you all!!!
Isn’t tsh the best indicator of thyroid hormone... - Thyroid UK
Isn’t tsh the best indicator of thyroid hormone replacement due to TT
The reason why you had a thyroidectomy might influence how you check thyroid hormone but I would say it's best to check all 3 thyroid hormone indicators, FT4, FT3 and TSH to assess status.
However if you have a target TSH level for cancer suppression there may be occasions when only TSH is checked.
If TSH is undetectable it would be sensible to check FT3 to ensure it stays in the lab range because over medication could cause other problems. I don't know if this is always done though.
Overmedication can cause a range of symptoms but they can vary for different people. A fast heart rate might be a noticeable symptom but it might manifest as anxiety.
Thank you! My TT was done for no reason, doctors wrongly advised me to remove healthy thyroid because of multinodular goiter that turned out to be normal. My FT3 and ft4 were always within the normal range on all 3 doses although they were lowest on 125, but still in the range.
For many of us once our thyroid is damaged by an autoimmune disease or for other reasons, the pituitary-thyroid feedback loop that is called TSH is also damaged and unreliable. For those of us with a part-functioning thyroid some of our hormones come from the thyroid and some from medication and the best measure of the amount of hormones in our blood is to actually measure the hormones in our blood - ie FT4 and FT3.
For those of us who take other medication than T4 ie NDT, T3 or a mix of T4 and T3, TSH is often suppressed and doesn't give an indication of our status regarding FT4 and FT3.
Thank you for your response. So what happens with us without thyroid? I feel almost the same on every dose from 125-150 but the only difference is that my tsh gets to low on higher dose but then FT3 and ft4 are in the middle/upper range where everyone on this forum recommend to be. Before when I had my thyroid my tsh was between 1,5 and 1.9, and I have never had thyroid issues before I lost it.
TSH can be an excellent marker for thyroid treatment and diagnosis. If it's high it reliably indicates a failed thyroid gland (except in rare cases). Measuring TSH has saved many babies from cretinism. However, a normal TSH does not guarantee a person does not have hypothyroidism or that their treatment is adequate. Doctors find it hard to accept this fact. Although TSH is useful in the majority of cases I have never been able to find a study that correlates TSH with signs and symptoms.
My view is that signs and symptoms along with the response to thyroid hormone treatment define thyroid status and should be given precedence over biochemistry. I feel TSH, fT3 and fT4 should always be assayed at first consultation, not just to get a more detailed picture but also to see if the axis is functioning correctly.
Thank you very much! I was always tested tsh alongside with FT3 and ft4, and it doesn’t look like I have a conversion problem as while tsh was decreasing my both FT3 and 4 were increasing proportionally. Now my FT3 and ft4 are in the upper range for ft4 and upper middle range for FT3 but tsh is low, so I am worried that my body gives me a sign to reduce the dose as this might be to high for me. I feel ok though. I have never had thyroid or any health issues prior to TT, and my tsh when I had mine/healthy thyroid was between 1.5 and 2.00. I am not sure if now without thyroid my levels should be different as now my body has to work harder and maybe I need more to convert t4 into needed t3.
There are lots of arguments that TSH is inadequate for dosing.
The biggest one that springs to mind is that most people will have a pretty low TSH once their dose is optimal and they are symptoms free. Once your TSH is, say 0.5, which is a fairly low number but many people need it lower than that to feel well, the TSH doesn't give much indication of which way to turn. You might still need an increase, but it's hard to find any evidence for it in that TSH. Whereas if you look at freeT4 and freeT3 alongside you've got loads more information.
And of course there are more complicated situations that can turn up. It's possible to have too much T4 but still have a high TSH. Its possible to have a high freeT4, low TSH, but still have very low freeT3. It's possible to have an impaired TSH response so all your thyroid hormones are low but TSH is also low.
Alongside all that, TSH response can have quite a bit of individual difference. It also changes as we age, and probably gets tired out as we take thyroid hormone or are sick for a long time. Doctors would have you believe it's completely objective and everyone's response is the same, but that has not been my experience at all.
Just a few that come to the top of my mind. There are many more!
Thank you very much! I was always tested tsh alongside with FT3 and ft4, and it doesn’t look like I have a conversion problem as while tsh was decreasing my both FT3 and 4 were increasing proportionally. Now my FT3 and ft4 are in the upper range for ft4 and upper middle range for FT3 but tsh is low, so I am worried that my body gives me a sign to reduce the dose as this might be to high for me. I feel ok though. I have never had thyroid or any health issues prior to TT, and my tsh when I had mine/healthy thyroid was between 1.5 and 2.00. I am not sure if now without thyroid my levels should be different as now my body has to work harder and maybe I need more to convert t4 into needed t3.
In general, people on thyroid hormone replacement will feel best with quite different blood tests than they had in health.
The freeT4 and freeT3 result you describe are a bit higher than you'd expect a person with a healthy thyroid to have, which would be around the middle of the range. However they are pretty ideal once on hormone replacement. You've probably even got room to increase the T3 a little if you still have symptoms and want an increase.
The same is true of TSH. Healthy people will have a TSH of around 0.8-2, but once on thyroid hormone replacement most people will feel better with it at the lower end. Either the bottom of the range or even well below the range.
Of course the thing we really care about is how much hormone is inside our cells where it does its work, and that's something the tests can't measure. They are just an approximation, so we have to rely on symptoms as the final indicator.
Doctors believe a lot of scare stories about a low TSH causing problems, but the arguments for this are quite circular. Most regulars on this forum have a completely suppressed TSH.
Thank you very much!!!this is very helpful
I am worried that my body gives me a sign to reduce the dose as this might be to high for me.
Your body WILL give you a sign if your dose of replacement thyroid hormones is too high. The sign is that you develop symptoms of hyperthyroidism --webmd.com/a-to-z-guides/ove...
Many doctors falsely believe that low TSH is the equivalent of hyperthyroidism, but they would be wrong. They need to look at the FT3 and FT4 levels. Why? Because the thyroid gland of people with hyperthyroidism produce high levels of thyroid hormones, and THIS is what causes problems, not low TSH per se.
Low TSH only tells you that the pituitary is for some reason not sending a message to the thyroid to make more hormones. If the reason is that you already have enough thyroid hormones, then no harm is done.
When doctors treat people who have had thyroid cancer, they purposely give sufficient thyroid hormone replacement to make the TSH go down to "suppressed." Strangely enough, very few of these patients ever develop the heart and bone problems that are associated with hyperthyroidism.
Usually, people with hyperthyroidism are not diagnosed until they already have heart or bone problems. So much for the wonderful state of thyroid treatment.
Thank you very much for your response, it has been very helpful. The weird thing is that I have been feeling ok on all doses (125,137 and 150) probably best on 125 when my tsh was 2.5 and t3 at the bottom of the range. I had to move it up to 150 as my tsh increased to 4.4 after I broke my leg. So now I am at suppressed 0.07 and doctor asked me to reduce, which I did to 137 and every few days 150, but it still stays at the same level. The only thing I noticed is that my periods are much shorter and lighter so that could be the sign that something is still off.
Sounds like you had autoimmune thyroid disease
It's important to have optimal vitamin levels on Levothyroxine
For full Thyroid evaluation you need TSH, FT4 and FT3 tested. Also EXTREMELY important to test vitamin D, folate, ferritin and B12
Low vitamin levels are extremely common, especially if you had autoimmune thyroid disease (Hashimoto's) diagnosed by raised Thyroid antibodies or Graves' disease
What vitamin supplements do you currently take?
Recommended on here that all thyroid blood tests should ideally be done as early as possible in morning and before eating or drinking anything other than water .
Last dose of Levothyroxine 24 hours prior to blood test. (taking delayed dose immediately after blood draw).
This gives highest TSH, lowest FT4 and most consistent results.
TSH is frequently suppressed on Levothyroxine. As long as FT4 and FT3 are both within range you are not over treated
Both FT4 and FT3 should be at similar percentages through range
Many people after thyroidectomy find conversion of FT4 to FT3 is poor. Getting vitamins optimal may help
Thank you very much!
This will not help you and I think the above advice is excellent, providing you feel well. Suppressing TSH after thyroid removal is done to stop regrowth of the thyroid and linked cancer cells. Having said that I still have some underactive thyroid symptoms despite a well suppressed TSH and "normal" levels of T3. Doctors will not change my T4 dose as levels appear ok and they do not wish to suppress my TSH any further. I still don't fully understand TSH and wonder whether it is even possible to raise levels to what might be considered normal if you don't have a thyroid. No doubt further research will reveal all.
Thank you! Yes, I was wondering that myself. Once you dose yourself tsh will not fluctuate if without thyroid.
You've had excellant answers.
I would like to add that treatment by the TSH alone has been shown to lead to under treatment. Many doctors worry about over treatment as they fear damage being caused but few doctor understand that under treatment also causes damage. It sounds like that whilst your doctor is performing all the blood tests, the doctor has been treating you according to your TSH level. This is unnecessary once on treatment & ypu doc should be taking most note of ypur actual thyroid levels and how you are feeling. A lot of people end up with a supressed TSH whilst on treatment. This doesnt matter so long as your thyroid hormones are in range. There is no set level of thyroid hormones that makes you well as each individual will vary a little to what level gets rid of their signs/symptoms. Many doctors dont understand this.
This is what an NHS endocrinologist who does know about thyroid replacement told me. Sadly he's retired now.
Thank you very much for your response, it has been very helpful. Yes, it makes complete sense. The weird thing is that I have been feeling ok on all doses (125,137 and 150) probably best on 125 when my tsh was 2.5 and t3 at the bottom of the range. I had to move it up to 150 as my tsh increased to 4.4 after I broke my leg. So now I am at suppressed 0.07 and doctor asked me to reduce, which I did to 137 and every few days 150, but it still stays at the same level. The only thing I noticed is that my periods are much shorter and lighter so that could be the sign that something is still off.
Yor doctor is treating you by your TSH......pointless! Constantly changing your dose up and down is confusing for your body and not helpful and is unnecessary once your sweet spot is found. Slight tweaks for either very cold or very hot weather maybe the only alterations needed. Levothyroxine is a storage hormone ie it has to be converted by your body to use it so your body is probably relying on the stored form to keep it going short term on the changing dose when its lowered. You are probably also kicking out more adrenaline to compensate when the dose is lowered so you dont notice....this is your body's way of compensating when the body is under stress - its a short term solution but eventually it will stress your adrenal glands.
I dont think your doctor understands what he/she are doing to be honest.
Thank you so much for your reply. They have just discovered that I have high testosterone but they claim it’s not related to the hormone replacement, so that could be an indicator although it could be something that I had before TT as it was never tested until now. When you say that dose should be changed when to cold and too hot, what do you mean, more or less when cold?
Maramonro am talking about extremes of weather eg a long heatwave or conversly a winter when we had a long spell of very low temperatures with snow. As you are in the process of finding your optimal dose I wouldnt tweak your dose as it will confuse matters, besides which here in the uk the weather is not currently extreme.
I am not a medic but my understanding is the under treatment or no treatment for hypothyroidism leads to the adrenals compensating. Am not aware of the role of testerone in this. Why you have high testerone I dont have the knowledge to explain. I do know that in women there is indeed a link between the thyroid circuit and female hormones and each can influence the other -I was told this by a specialist. She believed that addressing my thyroid hormone deficiencies would address this. She was right. My female hormones werent high but low. Whether this is the case for testerone I dont know. Hopefully someone else will know.
Thank you so much for your response. Much appreciated
I was extremely ill. My TSH was 1.6. Doctor said my thyroid was fine. Must be depression. Had private test T3 below range and T4 on bottom number of range. Took T3 and got better. Had I have listened to TSH only I would still be ill.
Thanks for your response, I completely relate. I had some terrible endo in Greece who didn’t care how I felt as the numbers were in “range”, and told me to see someone else as my blurry vision, confusion, brain fog and 50 heart rate is due to something else. She did know that I was perfectly healthy before doctors, including her wrongly advised me to remove such an important organ.
My thyroid was removed during parathyroid surgery, even though it still was working well was enlarged and knotty. We usually develop a large knot on thyroid when we get past 60. I take 150 mg levo, t4 and 10mg lio t3. I like to keep my TSH under one because that is when I feel normal. Hope that helps.
Hello, sorry to but in, do you take all 150 & 10t3 in one dose? I have no thyroid and is still struggling with my dose. I take 100t4 & 10 T3 all at once. Endo insists that might be too much because of my age. (64) Are yo around the same age? I see that you’re taking a higher dose, are you o.k with this dose? I’ve gained 10 lbs in 3 months and is still gaining, now looks 6 months pregnant, loosing all my hair, lots of muscle pain, very dry skin.
Any advice for me? Thanks.
I'm 74 and I take 75 mcg T3 only all in one go in the morning. And, I can assure you it isn't too much. 
Sounds as if your dose is actually too low. Why not start a new thread with your latest blood test results and let people advise you?
Thank you for taking the time to reply. I started a new thread with results, so I’m hoping members will advise. I always value your response.
You're welcome.
Hello, I am almost 72 and I take it all about 10 PM. That way I can eat whatever I want when when I get up. I am a little over 5ft 9 inches and a bit heavy but I feel good and weight is slowly going down. You probably need to up your t4 by 25mg and that will help, then later you might need to up again. Think you will feel much better.
Thank you! I will start with 12.5 increase and retest in 6 weeks. When I see the new labs, I will increase another 12.5 if needed. Thanks to all!!!!
Thank you very much! It does help
After a TT for a multinodular goitre that has gone bersek and was making me very ill indeed, it made no difference to how I felt irrespective of the dose of levothyroxine I took.
150 seemed to be best, 175 was obviously too much and 125 was obviously too little. I have no idea what my other results were, I was too ill to remember whether I even had any tests done at that time. I took numerous other non-prescription medicines and not one of them had any effect.
My doc gave up on me and told me to go away and sort myself out so I did, discovered NDT in 2014 and now I've given up on the doc as that was the answer.
I am glad you are feeling better now. It is really hard to find a doctor who knows his subject matter and actually cares about its patients. Take care
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