Thyroid-stimulating immunoglobulins

Thyroid-stimulating immunoglobulins (TSIs) are specialized antibodies produced by the immune system that mistakenly target the thyroid gland. These antibodies mimic the action of natural hormones called thyroid-stimulating hormone (TSH), causing the thyroid to become overactive. This leads to conditions like Graves' disease, resulting in symptoms such as rapid heartbeat, weight loss, and bulging eyes. Normally, antibodies help fight infections, but in this case, TSIs disrupt normal thyroid function by continuously stimulating it, leading to hormonal imbalance and related health issues.