High TSH and Low T3 levels

Can anyone offer any advice when your TSH readings are high but T3 levels are low. They keep wanting to lower my Synthroid, but when they do that my metabolism just about shuts down. Last readings showed T3 levels below normal. When I read about TSH, T4 and T3 it basically says that the T3 is what runs your metabolism. How can TSH be too high, but T3 be too low. What should be done to bring T3 up? Help!!! Meredith

Report post

11 replies. Join the discussion

Your T4 to T3 conversion isn't happening. Have you talked to your endo about adding Cytomel? Synthroid is T4 & Cytomel is T3. Maybe it will help.

Report post

T3 and T4 will both be low when TSH is high... generally this means an increase in Synthroid dose is needed, not a decrease. (I would be very confused by any endo who would suggest a dose decrease for a high TSH....that is not how it works). What are your lab values?
It is possible that your body is not converting T4 to T3 well if you have an ideal T4 & TSH and T3 is still low...in that case, adding Cytomel might help.

Report post

"How can TSH be too high, but T3 be too low"

because that's how it works.

http://www.endocrineweb.com/conditions/thyroid/how-your-thyroid-works

"When the level of thyroid hormones (T3 & T4) drops too low, the pituitary gland produces Thyroid Stimulating Hormone (TSH) which stimulates the thyroid gland to produce more hormones."

do you have thyroid cancer?

Report post

I'm sorry I didn't explain it better. My TSH numbers are low (which means it is high) and my T4 numbers are high, but T3 numbers are low. When they decreased my synthroid my metabolism just about shut down. After finding out my T3 numbers are low, I'm trying to figure out what has to happen to get those T3 numbers back to normal because boy do I feel it in my body. It's like my engine just stopped! It's confusing to me because I thought they should all be in tandum together and they are not and was concerned that if my synthroid has to stay decreased what the heck am I going to do about getting my metabolism to get back to normal. I had a thyroidectomy 16 years ago due to cancer and don't ever remember having T3 issues before. It's been a real learning experience to figure out what the TSH does, where it comes from and what the T4 and T3 do as well. So what I've learned is that synthroid is all T4 and that the body is supposed to convert that to T3. I don't know where that conversion takes place, but it doesn't appear to be happening for me very well. Now it's just figuring out how best to get all the numbers back in the normal range. They tried Armour thyroid on me years ago, and my body did not take to it very well - I felt terrible and ended back on the synthroid ever since.

Report post

If your TSH is low (or in the ideal range) and your T4 is normal/high, and your T3 is still low,then that means you could probably benefit from T3 supplementation. Have you tried asking for a small dose of Cytomel (T3) to be added along with the T4? The ratio in our bodies is very different from the ratio in Armour, so this might work for you even if Armour didn't.

Report post

No I have not, as I don't see my endo until next month. However, I wanted to gather all the information I could so I could work with her to get the best possible solution to help my weary metabolism and also try and understand this a little better before going to my appointment. I will definitely address the cytomel with her. Do you know if there are typically any side effects with this as I'm super sensitive to meds. Also read that there is a combo synthroid/cytomel med as well?? Thanks so much for all the great thoughts and advice.

Report post

Also wanted to ask if anyone can shed light on when/where the conversion takes place from the T4 to the T3. My understanding is that the T4 stores the hormone that gets converted to the T3 - where does this conversion take place? If it is done in the thyroid gland, then how does this conversion happen when you don't have a thyroid gland any longer and you are only taking synthroid which is the T4 hormone only? Thanks.

Report post

From the book, "Thyroid Cancer - A Guide for Patients" (available from ThyCa): page 11:
"In fact, only 20 percent of the circulating T3 in the blood is actually derived from the thyroid gland itself. The remaining 80 percent
comes from T4 released from the thyroid gland and circulating in the blood. The way this happens is that the circulating T4 attaches
to the thyroid receptor proteins in cells throughout the body (such as in the heart, liver, kidneys, etc). Within these cells, the T3 is generated by a process that removes one iodine molecule from t4, thereby generating T3."

Report post

the conversion happens in the cells.

Report post

endocrine web is really helpful (I think):

here's another link & excerpts:

http://www.endocrineweb.com/conditions/hypothyroidism/what-thyroid-hormone- replacement-therapy

When T4 hormones come into contact with other cells in the bloodstream, they give up an iodine atom to interact with those cells. When T4 loses an iodine atom, it becomes T3.

The benefit of taking only T4 therapy is that you're allowing your body to perform some of the actions it is meant to do, which is taking T4 and changing it into T3.

Report post

Due to a thyroid condition and subsequent fibromyalgia that was misdiagnosed for years... I have done alot of research and am still learning. I try to read and research as possible which has helped me immensely.. I believe that proper diagnosis and accurate testing is so essential. A book that has REALLY helped me is: The Thyroid Solution by Dr. Ridha Arem. Although very detailed, it is written so that the layperson can understand everything quite easily. Dr. Arem points out the harm and distress that doctors that are improperly trained, too busy or too disinterested to provide effective medical treatment can & do cause, which really got my attention. Due to total frustration and despair, many folks that have received this type of ineffective medical care have come to him for a second (or third, etc...) opinion. He discusses numerous types (and combinations) of tests to accurately identify specific imbalances as well as case studies that address all the different ways that thyroid imbalance can present in both women & men. Perhaps one of the most important things that I finally understood is that a thyroid imbalance ( the original test and resulting diagnosis) in not a constant and can be very complex and can be transitory in nature... He endorses/uses a "combination" T4 AND T3 protocol in many cases which, after I read about it, makes sense. I think this may be related to your question in some regard. He also points out the significance of lingering symptoms (anxiety, depression, weight flucuation) that occur after one is treated, and then tested normal, for thyroid imbalance when traditional testing & monitoring is used. I have found significant reason to associate my fibromyalgia with ongoing thyroid imbalance as well as determined an association between my thyroid imbalance and mono (which I had when I was younger). The more I know, the more I realize I need to know to fully understand how to deal with my thyroid-related challenges. Sadly, we patients have to become lay practioners and advocates to achieve any level of medical quality in our lives. Good luck to you. By the way, Dr. Arem's clinic is located in Houston, Texas where he is also on staff (Endocrinology) at Baylor College of Medicine. You might check out his website.

Report post

This journal entry is closed to replies. We close all journal entries after 90 days.

If there's something you'd like to say, here are some things you can do:

Things you can do