Thyroid gland: Functions & disorders - Signs & treatment

Thyroid gland: Functions & disorders - Signs & treatment

Ahmed Raza

The thyroid gland is a small gland wrapped around the trachea (windpipe), located in front of the neck. It is smaller in the middle, with two wide wings extending around the side of the throat, which makes it look like a butterfly. The thyroid is a gland that creates and releases substances that are vital for the body’s cells to function properly.

Thyroid disorders are commonly found and occur more frequently in females. However, a thyroid disorder can affect anybody, including men, teenagers, children, and babies. About 5% of people have some kind of thyroid disorder, and it can be temporary or life-lasting.

Functions of the thyroid gland

The thyroid gland makes two hormones that are secreted into the blood. These hormones are thyroxine and triiodothyronine. The main hormone is thyroxine, which contains four iodine atoms and is generally called T4. The other hormone contains three items of iodine and is named T3.

The hormone thyroxine is named T4 and converted to T3 in the body. It is biologically active and affects the activity of all the cells and tissues of the body.

The thyroid plays an important role within our body. It releases and controls thyroid hormones that consequently control metabolism. Metabolism is a process that transforms consumed food into energy. This energy is utilized throughout the entire body to keep all of the body systems working efficiently. Metabolism is like a generator, which takes in raw energy and uses it to power the entire human body.

Both the thyroid hormones, T3 and T4, enhance the basal metabolic rate. This has the following effects:


The thyroid is responsible for producing the hormones that play a vital role in all systems throughout the human body. If the thyroid makes either too little or too much of these hormones, it leads to a thyroid disorder. There are several different types of thyroid disorders, such as thyroiditis, hypothyroidism, hyperthyroidism, and Hashimoto’s thyroiditis.


In hypothyroidism, the thyroid gland doesn’t produce enough of its hormones. Sometimes surgery to operate on the thyroid gland or damage from radiation treatment causes thyroid disease. In the USA, it affects about 4.6% of people aging twelve years and older. However, most hypothyroidism cases are not of a serious nature.

Symptoms that too little thyroid hormone is produced include:

Conditions that can lead to hypothyroidism include:


This condition is a swelling or inflammation of the thyroid gland, and it can reduce the number of hormones produced by the thyroid.

Hashimoto’s thyroiditis

It is the most common cause leading to hypothyroidism in the United States. It has affected nearly fourteen million people in the USA. It can occur at any age, but it is more common in middle-aged females. This disorder occurs when the immune system of the body mistakenly attacks and damages the thyroid gland, and reduces its capacity to produce hormones.

Symptoms of Hashimoto’s thyroiditis can include:

Postpartum thyroiditis

This condition appears in 5 to 9% of women after they give birth to a child. It is normally a temporary condition.

Iodine deficiency

Iodine is necessary for the thyroid to produce hormones. Severe iodine deficiency is a major cause of hypothyroidism that affects several million people across the world.

A non-functioning thyroid gland

The thyroid gland is non-active from birth in some newborn babies. If this disorder is not treated in time, the child could have both mental and physical issues in the future. Each newborn baby is given a screening blood test after birth to check thyroid function.


In hyperthyroidism, the thyroid gland is overactive and produces many hormones. Hyperthyroidism affects about 1% of females. It is rarely found in males. Excessive thyroid hormone production can lead to the following symptoms:

Conditions that can lead to hyperthyroidism include:

Graves’ disease

It is an autoimmune disorder that occurs when the immune system mistakenly attacks the thyroid gland. This attack can make the gland overproduce the hormone responsible for controlling metabolism.

This disorder is hereditary and may occur at any age in males and females. It is more common in females aged 20 to 30. Other risk factors include smoking, stress, and pregnancy. If there is a high level of thyroid hormones in the bloodstream, the body systems speed up and cause signs and symptoms that are common to hyperthyroidism.

The symptoms may include:


It is a non-cancerous enlargement of the thyroid gland. The iodine deficiency in the diet is the main cause of goiter worldwide. Researchers estimate that goiter affects 25% of the population who are iodine deficient across the world.

A goiter can affect anybody at any age, especially in those parts of the world where foods are not enriched with iodine. A goiter is more common after the age of forty and females are more likely to have thyroid disorders. Other risk factors can include certain medication usage, pregnancy, family signs, medical history, and exposure to radiation.

If the goiter is not severe, there might not be any symptoms. However, the goiter may cause one or more of the following signs and symptoms if it grows too large, depending on its size:


This disorder may be painful or not felt altogether. In thyroiditis, the thyroid releases hormones stored in it. If it is subacute thyroiditis, this condition can continue for a few weeks or sometimes a few months. If the person has Hashimoto’s thyroiditis, hypothyroidism is typically permanent.

Excessive iodine

When you have excessive iodine in the body, the thyroid makes more thyroid hormones than required. Excessive iodine is found in some medications, such as amiodarone (a heart medication) and cough syrups.


Hypothyroidism or hyperthyroidism cannot be prevented in most cases. Hypothyroidism is generally caused by iodine deficiency in developing countries. This deficiency is rare in the United States due to the addition of iodine to table salt.

Hyperthyroidism is commonly caused by Graves’ disease (an autoimmune disease that is not preventable). An overactive thyroid can be set off by taking too many thyroid hormones. In the case of a prescription, the correct dose of thyroid hormones should be taken. Your thyroid can become overactive when you eat too many iodine-containing foods, such as fish, seaweed, and table salt.

You can’t prevent thyroid disease. However, you can decrease the complications by getting diagnosed at an early stage and following the treatment prescribed by the doctor.

Works cited

Last reviewed and updated by on May 27, 2022

Caitlin Goodwin, DNP, RN, CNM, is a Board Certified Nurse-Midwife, Registered Nurse, and freelance writer. She has over twelve years of experience in nursing practice.

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