What Causes Fluctuations In The TSH Levels?

Posted on Mon, 12 Sep 2016

Medically reviewed by Ask A Doctor - 24x7 Medical Review Team

Mon, 12 Sep 2016 Answered on

Mon, 3 Oct 2016 Last reviewed on

Question : I have been taking 150 mcg of Synthroid for a number of years after they finally stabilized the dosage. Over the last 6 months my TSH levels have been all over the place in spite of taking medication first thing in the morning by itself on an empty stomach, etc. My PCP had an ultrasound done on my thyroid and there are a lot of nodules (which are NOT cancerous), but that doesn't explain the widely swinging TSH levels. Thoughts?

Answered by Dr. Mirjeta Guni (1 hour later)

Brief Answer:
The TSH fluctuations are often unexplainable.

Detailed Answer:
Hello,
I can understand your concern.
Why TSH level fluctuate in different periods of life ( despite taking tha same dose of levothyroxine) is still unknown.
That is why TSH is recommended to be checked every 6 months even though you may have been for many years at a certain dose.
The lymph nodes ( if not cancerous) are indicative of inflammation but it dies not effect the TSH level and levothyroxine dosage.
So all we can do in these cases is to find the proper dose and try to maintain the TSH levels within the normal ranges.
Kind regards,
Dr.Mirjeta

Above answer was peer-reviewed by : Dr. Raju A.T