Share interesting facts about human body systems.

Normal Size of Thyroid Gland

Normal Size of Thyroid Gland

The thyroid gland is located in the throat. In this article, you will find more about the anatomy, size, structure and functions of the thyroid gland.
Madhura Pandit
Among, all the glands of the endocrine system, the thyroid is one of the largest. The endocrine system consists of glands which produce hormones. The endocrine glands are known as ductless glands, as the hormones that are produced are directly released in the blood. The thyroid gland produces thyroid hormones that are essential to carry out various functions in the body.

Where is the Thyroid Gland Located

The thyroid is a butterfly shaped gland located in the throat or neck region, just below the Adam's apple. If you wish to know the exact thyroid gland location, then note that the gland is located on the anterior part of the neck, near the trachea and larynx. The thyroid gland is wrapped around the wind pipe. The structure of the thyroid gland is also very peculiar which makes identification of the gland very easier. The thyroid gland has a right and a left lobe, which is connected by the isthmus. The gland is also covered with a fibrous sheath.

What is the Normal Size of the Thyroid Gland

The normal size, or range of size, of the thyroid gland in adults is 4 to 4.8 cm x 1.0 to 1.8 cm x 0.8 to1.6 cm. As mentioned above, the thyroid gland is one of the largest endocrine glands found in humans. The weight of this gland in neonates is about 2-3 grams. In case of adults, the normal weight of the thyroid gland should be in between 18-20 grams. The size of the thyroid gland can increase due to certain conditions like pregnancy or smoking frequently. These conditions are not termed as abnormal. However, due to certain reasons, the size of the thyroid gland increases. This can be a symptom of some abnormality like goiter. We will take a look at it later.

What are the Functions of the Thyroid Gland

The thyroid gland produces hormones like the tri-iodothyronine (T3) and thyroxine (T4). These hormones are essential for maintaining proper heart rate, body temperature and blood pressure. The thyroid hormones also play an important role in carrying out metabolism in the body. These hormones aid in physical as well as mental growth and development of the child. Secondly, calcitonin is also produced by the thyroid gland which helps in calcium homeostasis.

Now that we know about the normal size of the thyroid gland, let us try to understand the conditions that can cause the size of thyroid to increase. The two major disorders of the thyroid gland are hyperthyroidism and hypothyroidism. Hyperthyroidism is caused due to over production of the thyroid hormones; whereas hypothyroidism is caused due to the underproduction of these hormones. In both the cases, it is found that the size of the thyroid gland increases, resulting in goiter. Goiter can also be caused due iodine deficiency.

The thyroid ultrasound is a method used to check the size, position and shape of the thyroid gland. This method helps in diagnosing any underlying disorder. For e.g., if the doctor does not observe normal size of thyroid gland on ultrasound, he may check for the presence of conditions like goiter, tumor or cysts.

Lastly, it should be noted that if suffering from any thyroid disorder, you may also experience weight loss or weight gain, irritability along with the changes in size of the gland. Therefore, if you observe any symptoms that have persisted for a long time, it is wise to consult a doctor and undergo thyroid tests.
Doctor checking thyroid
Scanning of thyroid using ultrasound
Human Thyroid Gland Anatomy
Human Thyroid Location