Difference Between Thyroid and Parathyroid


Main Difference

The main difference between the thyroid and parathyroid gland is that a thyroid gland is a butterfly-shaped vascular organ that is located in the neck on the other hand parathyroid glands are actually four small glands of the endocrine system also present in the neck behind the thyroid gland and regulate the calcium in our body.

Thyroid vs. Parathyroid

The thyroid gland also produces another hormone called calcitonin, and the parathyroid glands secrete parathyroid hormone. The thyroid gland is present in the neck just under the laryngeal cartilage while parathyroid is present in the neck behind the thyroid gland. The thyroid gland is brownish red in color while parathyroid gland is mustard yellow. Thyroid gland secrets thyroid hormone while parathyroid gland secretes parathyroid hormone. Weight of thyroid gland is approximately 15-25 g; on the other hand, the weight of parathyroid is about 30 milligrams and is 3-4 millimeters in diameter. The thyroid gland consists of two lobes whereas the parathyroid gland is four in number.


Comparison Chart

The thyroid gland is a vascular organ located in the neckParathyroid glands are small endocrine glands that regulate the calcium in our body
Present in the neck just below the laryngeal cartilagesPresent in the neck behind the thyroid
Each lobe of the thyroid is 4 to 6 cm in length and 1.3 to 1.8 cm in thicknessThey are generally in the size of a grain of rice weighs approximately 30 milligrams and is 3-4 millimeters in diameter
Brownish red in colorMustard yellow in color
Hormones Production
Thyroxine, Triiodothyronine, calcitoninParathyroid hormones
Body’s metabolismRegulate calcium level in bones and blood

What is Thyroid?

The thyroid gland is a small butterfly-shaped vascular organ which is located in the neck. It is composed of two lobes, one lobe is on each side of the trachea, just below the voice box or larynx. These two lobes are connected by a small band of tissue which is known as the isthmus. Internally, the gland is made of follicles, which produce two hormones like triiodothyronine hormones and thyroxine. These hormones consist of iodine. About 5 percent is triiodothyronine, and 95 percent of the active thyroid hormone is thyroxine. Both of these need iodine for their synthesis. Thyroid gland secretion is regulated by a negative feedback mechanism which involves the amount of circulating hormone, adenohypophysis, and hypothalamus.


In the case of iodine deficiency, the thyroid is not able to make sufficient hormone. This stimulates the anterior pituitary to release the thyroid-stimulating hormone, which causes the thyroid gland to increase in size in a vain attempt to produce more hormones. But it cannot produce more hormones because it does not have the necessary raw material, iodine. This type of thyroid enlargement is called simple goiter or iodine deficiency goiter. Thyroid hormones affect three fundamental physiologic processes: cellular differentiation, growth, and metabolism. The thyroid gland also produces another hormone called calcitonin.


  • Calcitonin produced by the thyroid participates in the control of calcium and phosphorus homeostasis and have significant effects on bone physiology.
  • The thyroid gland controls much of our body’s metabolism.

What is Parathyroid?

The parathyroid gland is four in number, and they are the part of the endocrine system which regulates the level of calcium in our bodies. They are located in the neck just behind the thyroid gland where they are constantly monitoring the calcium level and also regulate the blood calcium level. Parathyroid glands are normally in the size of a grain of rice, but they can be as large as a pea size. Their color is mustard yellow. These glands also control the level of calcium in our bones, in our blood and throughout our body. They regulate the calcium by the production of parathyroid hormone. Calcium is an essential element in our bodies. Calcium also controls many organ systems of the body. Calcium is the only element in body which have its own regulatory system-the parathyroid gland. Parathyroid glands secrete parathyroid hormone or parathormone. Insufficient secretion of parathyroid hormone may lead to increased nerve excitability. The low level of calcium in the blood may trigger continuous and spontaneous nerve impulses, which then stimulate muscle contraction.



  • Parathyroid controls of phosphorus homeostasis and have significant effects on bone physiology.
  • Parathyroid glands also control the level of calcium in blood and bones.

Key Differences

  1. The thyroid gland is present below the laryngeal cartilage on the other side parathyroid gland is present behind the thyroid gland.
  2. In color, the thyroid is in brownish red, and parathyroid is in mustard yellow.
  3. The weight of thyroid gland is about 15-25 g whereas the weight of parathyroid is 30 milligrams.
  4. The thyroid gland controls body metabolism while parathyroid gland controls the level of calcium in blood and bone.


Conclusion of this article is that both the thyroid and parathyroid are present in the neck which secretes the different hormones that maintain our body’s metabolism and level of calcium.

Janet White

Janet White is a writer and blogger for Difference Wiki since 2015. She has a master's degree in science and medical journalism from Boston University. Apart from work, she enjoys exercising, reading, and spending time with her friends and family. Connect with her on Twitter @Janet__White

Adblocker detected! Please consider reading this notice.

We've detected that you are using AdBlock Plus or some other adblocking software which is preventing the page from fully loading.

We don't have any banner, Flash, animation, obnoxious sound, or popup ad. We do not implement these annoying types of ads!

We need money to operate the site, and almost all of it comes from our online advertising.

Please add to your ad blocking whitelist or disable your adblocking software.