1 Not all adenomas produce excess T-4, and doctors aren't sure what causes some to begin producing too much hormone. 2  Thyroiditis. 3  Sometimes your thyroid gland can become inflamed for unknown reasons. 4  The inflammation can cause excess thyroid hormone stored in the gland to leak into your bloodstream.
Forged steel is an alloy of carbon and iron that is compressed under extreme pressure to make a very hard and strong substance. It has been used for thousands of years to create all types of materials.
Steel is a metal alloy which includes iron and often some carbon. Every material is made up of atoms which are very small parts. Some atoms hold together quite well, which is what makes some solid materials hard. Something made of pure iron is softer than steel because the atoms can slip over one another.