What is the biochemistry behind the disease?

Grave's disease > thyroid hormone is over stimulated (HYPERthyroidism)


The pituitary gland secretes thyroid-stimulating hormone (TSH),  triiodothyronine (T₃) and thyroxine (T₄), which are primarily responsible for regulation of metabolism. They will bind to the thyroid-stimulation hormone receptor (TSHR) to produce thyroid hormones.


In Grave's disease, the body produces antibodies to the TSHR, resulting in the overproduction of the thyroid hormones.

They are 

• Thyroid stimulating immunoglobulins: act as long acting thyroid stimulants, activating the cells in a longer and slower way than TSH, leading to an elevated production of thyroid hormone.

• Thyroid growth immunoglobulins: bind directly to the TSH receptor and have been implicated in the growth of thyroid follicles.

• Thyrotrophin Binding-Inhibiting Immunoglobulins: inhibit the binding of TSH with its receptor. Some will actually act as if TSH itself is binding to its receptor, thus inducing thyroid function.

The autoantibodies produced in Graves' disease are not subject to negative feedback and will continue to be produced and bind to TSHR even when thyroid hormone levels rise too high. This results in hyperthyroidism, or an abnormally strong release of hormones from the thyroid gland.

Many factors can affect a person's susceptibility to Graves' disease, although the mechanism of initiation remains unknown.