Can subclinical hyperthyroidism get better or go away and return to normal?

Depends on cause: Hi. The main causes of hyperthyroidism are Graves' (almost never subclinical), a hot nodule (often subclinical), thyroid medication induced (common, often subclinical), and subacute thyroiditis (usually clinical in the hyper phase). Subacute thyroiditis hyper gets better on its own. Thyroid medication induced is easily corrected. Graves' & some hot nodules need treatment. Your endo will help.