Thyrotoxicosis
Thyrotoxicosis is a condition in which you have too much thyroid hormone in your body. Your thyroid — the butterfly-shaped gland in the front of your neck — makes and releases two hormones: triiodothyronine (also called T3) and thyroxine (also called T4). Together, they are referred to as thyroid hormones. Your thyroid and thyroid hormones play a large role in many important bodily functions, such as your body temperature, heart rate and metabolism. Metabolism is the pace at which your body processes things — how fast it burns the food you consume to make energy and heat. When you have thyrotoxicosis, the excess amount of thyroid hormones in your body launches your metabolism into high speed, which can cause symptoms such as a rapid heartbeat (tachycardia) and weight loss and certain complications.