Background

2. Where are the parathyroid glands?

The parathyroid glands are usually located in the neck behind the thyroid gland, although there are exceptions. While the baby is developing inside the mother's womb, the four parathyroids travel from the head area down to the lower neck, and usually end up near the thyroid gland. However, the parathyroid glands may not always follow this path and may end up in other locations in the neck or chest, called "ectopic" locations.

About 90% of parathyroid glands are found in normal locations. For the upper (superior) parathyroid glands, the normal location is next to and slightly behind the upper part of the thyroid gland. The upper parathyroid glands may also drop down next to the esophagus (the first part of the digestive tract that carries food from the mouth to the stomach) or into the chest, and can very rarely be found inside the thyroid. The lower (inferior) parathyroid glands have to travel farther during development and therefore can be found in a larger number of areas than the upper glands. The majority of lower parathyroid glands are found next to the lower part of the thyroid gland, but they can occasionally be found in the chest, high up in the neck by the jawbone, inside the thyroid gland, or next to the carotid artery.