The free t4 is the actual amount of thyroid hormone in your blood that your body has for immediate use.
The TSH can be elevated, but the actual hormone levels may still be OK.
It would still need treatment, but is not as bad as when the thyroid hormone is low.
When the TSH is high, the free t4 will eventually drop below normal. If the free t4 is still in range, it means that your thyroid is still able to keep up a bit by making just enough hormone.
Call your doctor's office and request a copy of your labs so you can see for yourself. You can post them here if you'd like, and we can give you some feedback on what the results mean.
I'm not sure what the t4 is. They did not give me that information. I'm not even sure if they tested for that. What would that indicate?
If the free t4 level was still in range, there is not much to worry about.
Did they test free t4 with the initial TSH of 15.17?