• The thyroid is a gland in the neck. Thyroid is shaped like a butterfly and lies at the front of the neck, under the voice box (larynx). The thyroid has two parts (lobes). The lobes are separated by isthmus (a thin piece of tissue).
• Four or more tiny parathyroid glands are behind the thyroid. Parathyroid glands are on its surface and make parathyroid hormone. The parathyroid hormone helps the body maintain a healthy level of calcium.

• Thyroid has two kinds of cells that make hormones:

1. 1. Follicular cells. Follicular cells make thyroid hormone, which affects the heart rate, body temperature, and energy level.
   2. C cells. C cells make calcitonin (a hormone that helps control the level of calcium in the blood).

•  A healthy thyroid is a little larger than a 20 cent coin. It usually cannot be felt through the skin.
• Thyroid disease may present as two group of disease either due to its function or nodules (cancer or non cancer) in the neck.

Updated:: 05/08/2020 []