If you have thyroid disease, you may experience some fluctuations in your thyroid hormone levels from time to time. These fluctuations can occur as your thyroid disease progresses.

What can cause a sudden increase in TSH levels?

Your TSH levels will be increased, if: Your thyroid gland is not working as it normally should. Your thyroid gland is infected or inflamed, as in Hashimoto's thyroiditis, or autoimmune thyroiditis. This occurs when your body is attacking your thyroid gland, for some unknown reason.

How long does it take for thyroid levels to change?

Drug therapy to normalize thyroid hormone levels can require two to three months. Generally, another year or two of continued drug therapy may be required before there is a true “remission” of the disorder. Keep in mind that drug therapy does not “cure” or bring about remission.