De Quervain Thyroiditis, also known as subacute granulomatous thyroiditis, is a condition characterized by inflammation of the thyroid gland. This inflammation leads to symptoms such as neck pain, swelling, and tenderness, as well as an overactive thyroid gland causing symptoms of hyperthyroidism. While De Quervain Thyroiditis is the commonly used term to describe this condition, it is also referred to as subacute thyroiditis or giant cell thyroiditis. These synonyms are used interchangeably by medical professionals to describe the same underlying condition. Understanding the various terms for De Quervain Thyroiditis can help individuals recognize and seek appropriate medical care amidst the discomfort caused by this inflammatory thyroid disorder.