Did your stress levels change? That could be an issue. Also a full work up on the pitutiary and thyroid should be done to rule out anything first.
Stress is a huge factor in the TSH levels bouncing like that. Diet too.
just wonder if you can check that the result of '15.0' is actually TSH, and not, say, any of the t's... sorry if this is a bum steer, but the result seemed a very round figure.
good luck
Over 6 years ago the AACE recommended that the reference range for TSH be changed from .5 - 5.0 down to .3 - 3.0. Unfortunately most labs and doctors have yet to adopt this change. So, all of your TSH results are over the current range limit and are an indicator of being hypo. TSH variability such as that may also indicate a need for the thyroid antibodies tests TPO ab and TG ab.
With that said, you really should also be tested for the actual, biologically active thyroid hormones, free T3 and free T4 (not to be confused with total T3 and total T4). FT3 is the most important because it is four times as active as FT4, and FT3 correlates best with hypo symptoms. Symptoms relief is what should be the most important consideration. In my opinion the most effective way to treat a thyroid patient is to test and adjust the levels of FT3 and FT4 with whatever type of meds are required to alleviate symptoms, without being constrained by resultant TSH levels. Frequently this will require that FT3 is moved into the upper part of its range, and FT4 adjusted to at least midpoint of its range. Please keep that firmly in mind as you proceed with more testing and treatment.
Also, you will need to make sure that the doctor who will be treating your thyroid problems is willing to treat your symptoms as I outlined above, rather than only wanting to treat you by your TSH level. TSH is a pituitary hormone that is affected by many variables and it does not correlate very well at all with hypo symptoms. It is therefore, inadequate for use as a diagnostic, by which to determine meds. Unfortunately many doctors still cling to the "Immaculate TSH" belief, and don't even want to test for the "Frees".
What prompted the thyroid testing? Do you have symptoms of thyroid problems? If you wil get the recommended testing done and results and reference ranges posted here, members will be glad to help interpret.