What is the Thyroid Gland?

T Thompson

The thyroid gland is a small gland that sits in the neck of humans and some animals. It is part of the larger endocrine system, and its main job is to secrete a unique thyroid hormone that helps the body do a range of different things, from managing temperature to processing energy from food. Keeping these hormones at balanced, regular levels is very important to overall health. The gland is typically quite small, but problems with the way it works can be very serious. People with persistent thyroid problems often take synthetic versions of thyroid hormone in order to keep their bodies functioning optimally, and a number of regulatory drugs are available depending on the specifics of the issue and the patient.

The thyroid gland is located in the neck, just below the Adam's apple.
The thyroid gland is located in the neck, just below the Adam's apple.

Location and Identification

This gland is the most visible and certainly the largest part of the endocrine system in humans, and in most animals, too. Broadly speaking, the endocrine system is what keeps hormones balanced and regulated. Hormones are internal chemicals that can trigger all sorts of things, from emotions to sensations organ functioning and metabolic efficiency.

Iodine is important for healthy thyroid functioning.
Iodine is important for healthy thyroid functioning.

The thyroid gland is located in the front part of the neck, just below the Adam's apple. People can’t usually feel or see it from the outside, in part because of how tightly it “hugs” or wraps around the trachea. It is butterfly-shaped, with "wings" known generally as the left and right thyroid lobes. In most cases the gland protects a number of nerves and muscle tissues by virtue of its shape and location.

The thyroid gland is prone to several disorders.
The thyroid gland is prone to several disorders.

Main Function

In healthy people, this gland functions in cooperation with the hypothalamus and the pituitary gland. The hypothalamus sends a signal to the pituitary gland through a hormone called the thyrotropin releasing hormone (TRH), and the pituitary gland then releases thyroid stimulating hormone (TSH) to the thyroid gland. Next, the thyroid releases T4 and T3 hormones, which enter the bloodstream and affect the metabolism of the heart, liver, muscle and other organs. The pituitary gland regulates the level of thyroid hormone in the blood and increases or decreases the amount of TSH released.

Thyroid functioning affects the body's metabolism.
Thyroid functioning affects the body's metabolism.

Hormone secretion is usually understood to be the thyroid’s primary responsibility. When thyroid hormones are imbalanced or out of synch, people are prone to experience a number of health concerns. Tracing problems back to the thyroid can be difficult without medical scans and tests for the presence of thyroid hormone, though issues are common enough that health care professionals in many parts of the world are specially trained in looking out for the signs and often run hormone screens as a matter of course when problems are suspected.

A malfunctioning thyroid is usually first detected by a physical exam of the thyroid gland.
A malfunctioning thyroid is usually first detected by a physical exam of the thyroid gland.

Hormone Regulatory Problems

Hypothyroidism, also known as “underactive thyroid,” is one of the most common thyroid gland problems, and it occurs when the thyroid fails to produce enough hormones. This disorder can often go unnoticed in its early stages, in part because symptoms are pretty common and can be attributed to a number of different illnesses. Weight gain, fatigue, and an increased sensitivity to cold are often some of the first effects people notice.

The thyroid gland functions in cooperation with the hypothalamus and the pituitary gland.
The thyroid gland functions in cooperation with the hypothalamus and the pituitary gland.

Hyperthyroidism, or “overactive thyroid,” is essentially the opposite; this condition causes an acceleration in metabolism, which can lead to sudden and dramatic weight loss. Irritability and anxiety are also common symptoms. Both overactive and underactive glandular problems can usually be corrected with medication, often in the form of synthetic hormones.

Irregular Growth Issues

Not all thyroid problems center on hormone production. Goiters, for example, are lumps on the throat that happen when the gland becomes inflamed. These are mostly benign, but at times they can compress the trachea or esophagus, which can make it hard to breathe or swallow. Thyroid nodules are similar; these are lumps that grow on the surface of the gland, usually in response to some sort or irritant but sometimes simply as a matter of course. Both can be removed surgically.

Thyroiditis is an inflammatory condition within the gland that often brings about pain and fever and has a wide variety of causes. This condition is easily treatable, and the symptoms usually go away on their own. On the more serious end of the spectrum is thyroid cancer. This particular type of cancer is usually very treatable, but a lot depends on how early the condition is caught and whether or not it has spread.

Located in the front of the neck, the thyroid gland produces hormones that regulate blood pressure, body temperature, heart rate, and the body's metabolism.
Located in the front of the neck, the thyroid gland produces hormones that regulate blood pressure, body temperature, heart rate, and the body's metabolism.

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Discussion Comments


@orangey03 – This happened to my cousin. She wasn't overweight at all before the surgery, but afterward, she expanded like a balloon!

Her doctor told her to stop eating things like white bread and cake and start eating whole grains instead. So, she switched to whole grain breads, pastas, and cereals. She also started eating spinach, beans, and other veggies with high nutrient content and fiber.

He also told her to walk for exercise every day. Since she has taken his advice, she has lost a good portion of the weight that she put on after the surgery. Maybe this could help you, too.


I had to have part of my thyroid gland removed a few years ago, and I've been having major issues with weight gain. I actually eat less than I used to, yet I have put on fifty pounds!

I don't understand it. Sometimes, I only eat half a burger and a salad for lunch and about the same amount of food at dinner, but I still gain weight.

I know that this is related to my thyroid gland, but I don't know what I can do about it. I'm already on medication because of the surgery.


@Perdido – It is possible to have borderline hypothyroidism. I know for a fact that I suffer from this, but because my levels fall within the normal range, my doctor cannot treat me for it.

I have all the underactive thyroid gland symptoms, so it is frustrating that there is nothing I can really do about this. Like you, I wear a sweater everywhere, and I also take naps and try to eat healthy foods to combat the fatigue.


@comfyshoes – I went through a period where I was cold all the time. I kept turning the air off at work, and everyone else would turn it back on. I had to wear a warm sweater even in the summer!

I also felt tired and weak all the time. Because of all these symptoms, my doctor did a thyroid gland hormone level test.

Much to my disbelief, it came back normal. I wonder if it is possible for a person to have borderline hypothyroidism?


Why does goiter happen?

My sister had an ultrasound recently after the doctor noticed some inflammation in her throat during the physical exam. It turns out it was goiter, the ultrasound showed an enlarged thyroid gland. My sister has to be on medications now. I'm worried about her.

@simrin-- Well, do you know what the cause of your hypothyroidism is? There are several underlying conditions that could be causing it like iodine deficiency, infection or Hashimato's disease. So it really depends.

I don't think stress causes thyroid gland to dysfunction. But stress has been shown to weaken our immune system by suppressing hormones that keep our immune system strong.

So if you were really stressed and this weakened your immunity, your body might have not been able to fight off an infection that damaged your thyroid.


@leilani-- Really?

Can stress cause our thyroid to dysfunction?

I went through a really stressful several years recently and now have been diagnosed with hypothyroid. I can't believe that stress could have affected my endocrine system like this. It's so scary.


An under active thyroid gland creates a series of symptoms that worsen if left untreated.

Usually people with underactive thyroid glands have difficulty losing weight and steadily gain weight although their food intake is moderate.

They also suffer from coarse skin and begins to show signs of hair loss.

A person with a low thyroid gland is also sensitive to cold and is usually cold when everyone else is comfortable. This condition can also lead to constipation, irritability and depression.

It can be treated with hormone therapy to balance the hormonal levels and an enhanced diet of healthy foods.

People undergoing thyroid gland treatment for an underactive thyroid gland also should eat foods that are considered low glycemic foods.

Glycemic foods tend to turn the food into sugar in the blood stream and sugar significantly lowers the metabolism which is why these types of food like rice, pasta, and processed or sugary foods should be limited.

Also, exercise should be done daily in order to raise the overall metabolic rate. Daily exercise also reduces other symptoms of a low thyroid problem significantly.


Constant stress has negative effect on the workings of thyroid gland. Taking time to relax, and learn how to manage stress, is very important.

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