Difference Between Thyroid and Hormones

The thyroid gland and hormones are both important components of the endocrine system in the human body. While they are related and have a significant impact on various bodily functions, there are distinct differences between them.

What is Thyroid?

The thyroid functions as an endocrine system organ. Two different hormones produced by this gland control metabolic rate.

Structure − Thyroid anatomy consists of four lobes located in the base of the human neck. In the lobes, follicles are found, which are encased in epithelia. Follicles are where hormones are synthesised.

Function − The thyroid's two hormones help regulate metabolic rate. Production of hormones includes thyroxine (T4) and triiodothyronine (T3). Each of the thyroid's follicles is responsible for producing them from iodine molecules.

Regulation − Hypothalamus and anterior pituitary gland hormones regulate thyroid hormone release. Each of these brain areas is part of a negative feedback loop that regulates their respective activities. The hypothalamus becomes active when there are insufficient levels of thyroid hormone in the blood. Thyrotropin-releasing hormone is secreted as a result, prompting the anterior pituitary to release thyroid-stimulating hormone, which, in turn, encourages the thyroid to produce and release the two thyroid hormones into the circulation.

Disorders − Problems with the thyroid gland often fall into two categories: either the gland is producing too little or too much of the hormones that regulate metabolism. Due to an underactive thyroid, a lack of hormone production can cause a sluggish metabolism, leading to weight gain, as well as dry, brittle hair. In contrast, a person with an overactive thyroid frequently has high heart rate and weight loss.

What are Hormones?

Hormones are chemical messengers that are produced by the endocrine glands and released into the bloodstream to regulate various bodily functions, including growth and development, metabolism, and reproduction. In the female body, the two primary hormones involved in the reproductive cycle are estrogen and progesterone. Estrogen is responsible for stimulating the growth and development of the female reproductive system, while progesterone plays a critical role in preparing the uterus for pregnancy.

Any hormone associated with a specific receptor results in a cell-specific response. The response may be −

  • Rapid non-genetic response;

  • Slower genetic response – the receptors affect gene transcription and increase or decrease the release of given proteins.

  • Most often the hormones are produced by the endocrine glands, but they can be also secreted from other tissues and organs.

The secretion of hormones is highly dependent on the body’s condition. For example, the blood sugar levels affect the production of insulin; the concentration of potassium ions in blood plasma affects the synthesis of parathyroid hormone, etc.

The hormones can be −

  • Steroid hormones

  • Polypeptide hormones

  • Amino acid hormones

Hormones may circulate in the blood to reach distant target cells or remain where they are secreted and act on the nearby cells. There is a specific type of hormones, called autocrine hormones, which act on the cells which have secreted them.

Differences: Thyroid and Hormones

The following table highlights the major differences between Thyroid and Hormones −





The thyroid is the largest endocrine gland in the human body.

Hormones are chemical substances produced by the endocrine glands, regulating the processes of growth, development, and metabolism in the body.


The thyroid is located in the front of the neck, just below the larynx and over the trachea, and moves with the larynx.

Hormones travel through blood, tissues, and organs to deliver their messages to initiate, stop or modulate most of the known processes in the body.


In the embryonic stage of development of human organism, the thyroid appears as an epithelial proliferation of the front wall of the pharynx.

Many tissues and organs in the body are able to secrete hormones. Most often hormones are secreted by the endocrine glands.


The thyroid produces the hormones thyroxine and triiodothyronine. It regulates the metabolism, function of the heart, digestive function, muscles, brain development, etc.

Hormones initiate, stop or modulate most of the known processes in the body: growth and development, metabolism, sexual functions, mood, behavior, immune system regulation, hunger, etc.


In summary, the thyroid gland and hormones are both important components of the endocrine system, but they have distinct differences in their functions and mechanisms of action. The thyroid gland produces and releases thyroid hormones, which regulate metabolism, growth, and development.

Hormones, on the other hand, are chemical messengers produced by various glands throughout the body that regulate a wide range of bodily functions. Understanding the differences between these two important components of the endocrine system is crucial for maintaining optimal health and wellbeing.

Updated on: 07-Apr-2023


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