Thyroid Disorders Community
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Avatar universal

Anyone noticed that their thymus gland has grown since taking Synthroid?


Dec 27, 2012
To: anyone

I was diagnosed with hypothyroidsm in May, 2009. I took levothyoxine and was retested after 6 weeks. My doctor also checked the free T3 and T4. She made adjustments and my tsh went from 6.1 to 4.6. she felt I should be super  now. But the truth was, I only felt a bit better. One Monday, I did...I felt so good it was almost like I used to feel. but by Tuesday, it was wearing off and by Wednesday it was gone.

After about a year I noticed I was developing a lump in the upper center of my breastbone. I've been watching it for a couple years now. this week I checked online for info on what is located in this area. The Thymus gland is in the same location. It is supposed to hold white blood cells and fat and shrink after puberty. But mine has grown enough to push the breastbone up.

I have an appointment January 4, 2013 and plan to take some info I found on the Internet that suggested there is a connection between the thymus and the thyroid glands. It was on www.ehow.com and it states "According to the Womens' Guide toThyroid Heath, low thyroid function can cause a reduction in the production of hormones by the thymus galnd."

So my question is, if that statement is true can the Synthroid I'm taking to raise my low thyroid also cause the thymus to grow????

Has anyone else had this experience with their thymus?

6 Responses
1756321 tn?1547098925
A benign (non cancerous) growth or tumour may be the cause of an enlarged thymus. Thymoma are the most common tumour of the thymus.
People with thymoma often have autoimmune diseases as well. These diseases cause the immune system to attack healthy tissue and organs. They include:

Myasthenia gravis
Acquired pure red cell aplasia
Lupus erythematosus
Rheumatoid arthritis
Sjögren syndrome

Thyroiditis is inflammation of the thyroid gland. There are various types of thyroiditis however Hashimoto's thyroiditis is the most common cause of hypothyroidism in the western world.  

Tests for Hashimoto's thyroiditis include thyroid antibodies - Thyroid Peroxidase antibody (TPOAb) and/or Thyroglobulin antibody (TgAb). Approximately 10 - 15% may be antibody negative however. In this case, an ultrasound or FNA biopsy can help confirm a suspected diagnosis.

The TSH therapeutic goal for primary hypothyroidism is stated to be 0.5 - 1.5 mU/L in one study to 0.5 to 2.5 mU/L in another study. That said, the TSH is just one lab test to take into account along with other thyroid labs and symptoms.
Avatar universal
Thank you for the info. I'll share it with my doctor this week. I may need to have some tests done. I'll post the results.
1756321 tn?1547098925
No problem. :)  Just an edit here: Thyroid Peroxidase antibody (TPOAb) and Thyroglobulin antibody (TgAb). Both tests are recommended.
4524270 tn?1355881950
I read your post and wanted to comment on TSH levels.

4.6 would be considered hypo on the new lab ranges, and especially if you are symptomatic. My optimum TSH in years past --with complete removal of symptoms-- was around 1.5. Yours is probably lower too, but even with a lower TSH, if you still have symptoms, levothyoxine might not be the best choice.

Definitely get both antibodies tests.

The removal of symptoms should be the goal, not a lower number on a lab. No Dr should ask a patient to settle for being miserable, no matter what your age.

Avatar universal
thank you for the info...I did talk to my GA doctor about the 4.6 on my tsh vs the 3.5 I had in Ohio with my doctor there last year....she said that different labs use different equipment and the numbers don't mean much. I had not heard this before. Before she saw the results of my tsh she had cut my Synthroid from 100mcg to 50 mcg. When I asked her why she said that was what was on the bottle I brought in. I don't have that bottle but the Pharmacy receipt I have saved for tax purposes says it was 100 mcg. I now need to clear my throat more frequently, again. So she wrote a prescription for 75 mcg which costs three cents more per pill than the 100 mcg.  I thought she was sending in the new prescription for 100 mcg...I found it was 75 mcg when I picked it up. I'm not the type who likes to take a lot of meds but if I need them, I will take them. I don't want the low thyroid to cause harm to other parts of my body. I'm sorry this is so long...thanks again
Avatar universal
Hey Ruth,

I know it has been a few years since you've posted about this, but I just discovered this thread today and although I am a 20 year old male, I have something which I believe to be very similar to what you have.

I also have hypothyroidism that I have only recently been diagnosed with but have more or less felt the effects of for the past year and I too have been sort of scared by this lump that has appeared under my upper chest in what sounds like the same place you have found one.

I first noticed this about two years ago but just assumed it was an over-developed upper pectoral muscle, but now I do not believe this is the case.

I am not sure what state you are in now or if you have any news, but I'd love to hear from you and let you know that you are not alone!
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