What You Should Know About Your Thyroid

| Posted On Jan 30, 2012 | By:

Do you know what your thyroid is? Do you know where in your body it is located, or what it does? If you answered “no” to any or all of these questions, you are far from alone. Many people know little to nothing about this small but extremely critical gland.

According to the American Thyroid Association, an estimated 20 million Americans have some form of thyroid disease and more than 12 percent of the U.S. population will develop a thyroid condition during their lifetime.

About Your Thyroid

The thyroid gland is a small, butterfly-shaped gland located in the base of the neck just below the Adam’s apple.  Although relatively small, the thyroid gland influences the function of many of the body’s most important organs, including the heart, brain, liver, kidneys, and skin. Thyroid hormones influence how the body breaks down food and either uses that energy immediately or stores it for the future, regulating our body’s metabolism. Ensuring that the thyroid gland is healthy and functioning properly is important to the body’s overall well- being.

Thyroid Conditions

Thyroid disease takes on two basic forms. Your thyroid may not function properly, making either too little or too much thyroid hormone. Or it may have a structural abnormality. It may just be enlarged, which is known as a goiter, or it may have a nodule or lump—most of which are benign.

Over- or Under-Production of the Thyroid Hormone

Hypothyroidism refers to an underactive thyroid, occurring when the thyroid gland produces less than the normal amount of thyroid hormone. The result is the “slowing down” of many bodily functions. Of the nearly 30 million people estimated to be suffering from thyroid dysfunction, most have hypothyroidism.

In its earliest stage, hypothyroidism may cause few symptoms, since the body has the ability to partially compensate for a failing thyroid gland by increasing the stimulation to it, much like pressing down on the accelerator when climbing a hill to keep the car going the same speed. As thyroid hormone production decreases and the body’s metabolism slows down, a variety of problems may result.

Hyperthyroidism develops when the body is exposed to excessive amounts of thyroid hormone. This disorder occurs in almost one percent of all Americans and affects women five to ten times more often than men. In its mildest form, hyperthyroidism may not cause recognizable symptoms. More often, however, the symptoms are discomforting, disabling, or even life-threatening.

When hyperthyroidism develops, a “goiter” (enlargement of the thyroid) is usually present and may be associated with some or many of the following symptoms:

Autoimmune Thyroid Disorders

An autoimmune disorder is an abnormality of the immune system, in which the body attacks normal structures with its own antibodies, known as autoantibodies. Autoimmune thyroid disease is the most common type of autoimmune disorder. We do not know for sure why some people have it and others do not, but it runs in families and is more common in developed parts of the world. Families with autoimmune thyroid disease are more likely to have members with other autoimmune diseases such as lupus or type 1 diabetes.

Hashimoto’s thyroiditis (named after a Japanese physician), also called autoimmune or chronic lymphocytic thyroiditis, is the most common form of autoimmune thyroid disease. It is an inherited condition that affects over 10 million Americans, is about seven times more common in women than in men, and is the most common cause of hypothyroidism in the United States.  A goiter may also form with or without hypothyroidism. Hashimoto’s thyroiditis may remain undiagnosed for years until an enlarged thyroid gland or abnormal blood tests are discovered as part of a routine examination. When symptoms do develop, they are either related to local pressure effects in the neck caused by the goiter itself, or to the low levels of thyroid hormone.

Graves’ disease (named after Irish physician Robert Graves) is also an autoimmune thyroid disorder that frequently results in thyroid enlargement and hyperthyroidism. In some patients, swelling of the muscles and other tissues around the eyes may develop, causing eye prominence, discomfort or double vision. Like other autoimmune diseases, this condition tends to affect multiple family members. It is much more common in women than in men and tends to occur in younger patients.

Interestingly, Graves’ disease and Hashimoto’s thyroiditis often occur in the same family. So while one member of a family has an underactive thyroid, other members of the family may have an overactive thyroid.

Thyroid Nodules

The term “nodule” refers to any abnormal growth or lump in the thyroid.   The vast majority of thyroid nodules are benign (they are not cancerous), but a small proportion of thyroid nodules (about 1 in 10) do contain thyroid cancer.

Nodules often go undetected and are usually discovered during a routine exam by your doctor, but some people do notice a lump on their neck.  You can do a self-exam at home to see if you can detect nodules.  A few patients with thyroid nodules may complain of pain in the neck, jaw, or ear. If the nodule is large enough, it may cause difficulty swallowing or even some shortness of breath if it is pressing on the windpipe.

If a nodule is found to contain cancer, the good news is that thyroid cancer is usually curable.  The key is to have routine physical exams so that a nodule can be detected early.

Diagnosis and Screening

Since many symptoms of a thyroid condition are broad and subtle, they may be caused by many things.  The best way to identify if your thyroid is not working properly is through a blood test that measures the amount of thyroid-stimulating hormone (TSH) in your system.  Your doctor can then determine if you have a thyroid condition, what it may be, and how to treat you.  Sometimes treatment is not necessary, but periodic follow up is always required

Unfortunately, despite the prevalence of the disease and the relative accuracy of the blood test results, experts disagree about screening for TSH; in other words, doing the blood test as a general check and before a person has specific symptoms.  But if you have a personal or family history of thyroid disease, or an autoimmune disease or any of these conditions, your doctor should be checking your TSH level.

Studies are also exploring whether or not universal TSH screening should be done in all women planning a pregnancy or who are pregnant, given the thyroid hormone is necessary for normal brain development, and in early pregnancy, babies get thyroid hormone from their mothers until their own thyroids develop.

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About Dr. Jeffrey R. Garber

Dr. Jeffrey R. Garber is Chief of Endocrinology at Harvard Vanguard Medical Associates and a member of the Beth Israel Deaconess Medical Center and Brigham and Women’s Hospitals endocrine divisions. He is an Associate Professor of Medicine at Harvard Medical School, where he has trained many endocrinologists. Dr. Garber is a Past President of the American Association of Clinical Endocrinologists (AACE) and President-Elect of the American College of Endocrinology. His book, The Harvard Medical School Guide to Overcoming Thyroid Problems, was written for members of the lay public interested in learning about thyroid disorders.


  1. Dear Dr. Garber,

    Thank you for your very thorough explanation of the Thyroid gland. I have an enlarged Thyroid on one side, and it was most helpful to read about the variety of conditions. I never realized the Thyroid controlled so many important functions. This will help me to be more aware of my condition.
    Thank you!!!

    Comment by Sally Truesdale on February 29, 2012 at 8:34 pm
  2. Do you recommend all nodules be removed? I currently have a nodule that was found in 2007. My endocrinologist decided to wait and watch it. No other ultrasound tests have been done since then to determine if any change has occurred.
    Thank you for your help.

    Comment by Kellie on October 11, 2012 at 7:30 am
  3. Hi, Kellie. Not knowing your full medical history, it’s difficult to comment. But if you are concerned, you should bring this concern up with your own doctor and confirm the treatment plan and timing is still correct for you. I hope this blog will help you to have an even more informed conversation with your doctor.

    Comment by Harvard Vanguard on October 22, 2012 at 11:56 am
  4. Dear Dr. Garber,
    I have hypothyroidism and have been taking low dose levothyroxine (25mcg). My father had hypothyroidism, but I do not know if it was Hashimoto’s disease or not. It is important for me to know whether my hypothyroidism is due to autoimmune disease (Hashimoto’s) or not? Is there any difference in the way it would be treated? And (last question), how often should I have blood work done to ensure that my hormone levels are remaining in the normal range?
    Thank you for the thyroid article. I hope to hear a reply despite the fact it has been some time since the article was posted.

    Comment by Diane Burns on April 17, 2014 at 5:18 pm
  5. Hi, Diane. Have you broached your questions with your doctor? Your doctor is in the best position to answer these, as he or she has access to and can review your lab results and determine the best course of treatment based on those and your medical history.

    Comment by Harvard Vanguard on April 30, 2014 at 2:46 pm
  6. Do any of the doctors do the free t3 and t4 testing? I have been switched to Armour, but am still deeply exhausted. If I engage in any physical activity, I’m down for days. I do feel better with the Armour as opposed to the Levothyroxin. Now I’m wondering if the adrenals could be involved. Is there anyone I can speak to?

    Comment by Karen Fallon on August 26, 2014 at 10:24 am
  7. Hi, Karen. I’d suggest you contact your doctor and understand what steps he or she would recommend you take. Your doctor has access to your medical history and can provide the best advice for you.

    Comment by Harvard Vanguard on August 27, 2014 at 12:19 pm

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