Common Myths About Thyroid Disease

Despite advances in our understanding of thyroid disease, there remain numerous myths and misunderstandings that stand in the way of the proper diagnosis and treatment of hypothyroidism (low thyroid function) and hyperthyroidism (an overactive thyroid gland). Being aware of them, and learning more about common mistakes to avoid, can help you be a more active participant in your care plan and feel your best.



  • Your thyroid stimulating hormone (TSH) levels are fine if they are in the normal range.


  • A "normal" TSH depends on the reference range your doctor is using, your age, and your TSH results in relation to other thyroid function tests.

Moreover, there remains some controversy as to what is considered "normal" in TSH testing (the amount of thyroid stimulating hormone, or TSH, in a blood sample). While the vast majority of laboratories in the United States classify normal as being between 0.5 milliunits per liter (mU/L) and 4.5 to 5 mU/L, others believe that the upper limit should be closer to 2.5 mIU/L, meaning that more people would be considered to have hypothyroidism and placed on treatment.

Conversely, as thyroid function invariably decreases with age, an upper normal range of 6.0 to 8.0 mIU/L may be more appropriate for people 65 and over.

To get a more evaluative picture, your TSH needs to be measured in relation to the thyroid hormones it stimulates, namely T4 and triiodothyronine (T3), as well as your medical history, co-occurring conditions, and symptoms. Based on these interlinked factors, your TSH reference range may need to be adjusted to better manage your disease on an individual basis.


  • You only get symptoms if your TSH is outside of the normal range.


  • Symptoms can occur even when TSH levels are normal and are on fully optimized treatment.

When reading a thyroid lab report, your TSH levels will be interpreted based on its location in the reference range. The reference range includes the high and low values between which your TSH would be considered normal. Higher TSH values correspond to lower thyroid hormones (hypothyroidism), while lower TSH values related to higher thyroid hormones (hyperthyroidism).

What this suggests is that having a TSH within the normal range means that your thyroid gland is functioning normally. And in many cases that is true.

However, a TSH test provides only a glimpse of your overall health. Some people will still develop thyroid symptoms despite having results in the normal range. You may even be on treatment and positioned in the "sweet spot" at the center of the reference range (known as the optimal reference range) and still feel ill.


  • Synthroid is the only drug that can treat hypothyroidism.


  • There is a variety of other options that may be used in combination with Synthroid or on their own.

If faced with hypothyroidism, there are some people who will insist that there is only one drug used for hormone replacement therapy: Synthroid. Synthroid is the most commonly prescribed brand of a synthetic T4 hormone known as levothyroxine. There are other levothyroxine brands on the market as well, including Levoxyl, Tirosint, and Unithroid.

While levothyroxine is considered the gold standard for the treatment hypothyroidism, it is certainly not the only drug available.

Despite the fact that neither the American Association of Clinical Endocrinologists (AACE) nor the American Thyroid Association (ATA) actively endorses its use, the synthetic T3 hormone Cytomel (liothyronine) is being increasingly used to improve symptoms in people unable to achieve relief with levothyroxine alone.

Another drug used for more than a century to treat thyroid disease is natural desiccated thyroid (NDT), which is derived from the thyroid glands of pigs and cows. The FDA-approved medication, marketed under the brand names Armour Thyroid, Nature-Throid, NP Thyroid, WP Thyroid, and others, contains both T4 and T3.

While not endorsed for use by the AACE or ATA, NDT is considered by some to be just as effective as the synthetic hormones in treating mild hypothyroidism. Former Secretary of State Hillary Rodham Clinton is among the growing number of people who use NDT to manage their thyroid conditions.


  • Hyperthyroidism always causes weight loss.


  • Some people with hyperthyroidism can actually gain weight.

Some people will equate thyroid disease to weight problems, believing that you will gain weight if you have hypothyroidism and lose weight if you are hyperthyroid. While both of these things can occur, the changes in weight can vary from one person to the next.

With hypothyroidism, the median weight gain is relatively modest, usually between 5 and 10 pounds. The weight gain tends to worsen in tandem with the severity of your condition. What this means is that some people will not gain any weight if their condition is mild, while others will put on 15 pounds or more despite eating less. This is especially true if you were overweight or obese prior to your diagnosis.

With hyperthyroidism, the excessive production of thyroid hormones can speed up your metabolism and cause you to lose weight unexpectedly. But that doesn't mean that everyone will do so. A subset of people with hyperthyroidism will actually gain weight due to an increased appetite and craving for carbs. Everything from diabetes to thyroid inflammation (thyroiditis) can potentially trigger weight gain in the face of hyperthyroidism.

If experiencing unintended weight gain or loss, speak with your doctor. While changes in treatment may help, diet and exercise should be addressed as part of a holistic approach.


  • You can tell someone has Graves' disease by their bulging eyes.


  • While many people with Graves' do develop thyroid eye disease, just as many do not.

Bulging eyes are commonly associated with thyroid disease. Also known a thyroid-associated orbitopathy (TAO), the condition is often accompanied by eye dryness, blurred vision, or double vision.

TAO most often develops in response to an autoimmune disorder known as Graves' disease in which the body's immune system attacks the thyroid gland, leading to the development of hyperthyroidism.

While TAO is a common feature of Graves' disease, not everyone with the disease will get it. Likewise, in those who do develop TAO, bulging eyes is only one of the possible symptoms of the thyroid condition.

The likelihood and severity of TAO are influenced by genetics, environment, aging, smoking, and the level of thyroid dysfunction. According to research from Kurume University School of Medicine, between 25 percent and 50 percent of people with Graves' will have clinically significant TAO. Around 2 percent of people with Hashimoto's disease, an autoimmune cause of hypothyroidism, will also experience TAO.

Most cases of TAO tend to resolve after several years and may be relieved with artificial tears or oral steroids. If the pain or vision impairment is severe, surgery may be needed.


  • You should take iodine supplements or iodine-containing herbs if you have thyroid dysfunction.


  • Most people in the United States do not have iodine deficiency. Supplementation is usually not necessary (and can have negative consequences).

Though the predominant cause of thyroid problems globally, iodine deficiency is not the main cause of hypothyroidism in the United States. Though the thyroid gland needs iodine to synthesize thyroid hormones, the deficiency of iodine is uncommon in America due to the iodization of table salt.

To this end, treating hypothyroidism with iodine supplements or herbs such as kelp, bladderwrack, and bugleweed—a practice common among naturopathic practitioners—is more likely to cause harm than good in American patients. In addition to possibly making your condition worse, it can result in rare cases of toxicity. High doses can cause fever, stomach pain, nausea, vomiting, and a burning sensation in the mouth and throat.


  • Only women get thyroid disease.


  • Both males and females of any age can develop a thyroid condition.

It is true that women are five to eight times more likely to develop thyroid disease than men. The risk in women tends to increase during puberty, pregnancy, and the postpartum period immediately following delivery. There is also an increased risk during early menopause as hormones start to decline. 

But the simple fact is that thyroid disease can occur at any age in both sexes. Among men, the risk increases with age. In terms of prevalence, around two million American men are believed to be living with some form of thyroid disease.

Among this population of men, the rate of thyroid cancer is almost in tandem with that of women with thyroid disease, rising by 16.5 percent and 20.6 percent respectively from 1999 to 2009, according to research published in the journal Thyroid.

Some babies are also born with congenital hypothyroidism, a condition that affects female and male babies by a ratio of two to one.


  • Your basal body temperature (BBT) can help diagnose and manage hypothyroid disease.


  • While the thyroid gland regulates your BBT, this measure can provide no evaluative insight into the nature, severity, or even presence of thyroid disease.

While hypothermia (low body temperature) is a known symptom of hypothyroidism, using your basal body temperature (BBT) as a diagnostic tool is seriously flawed. Although your thyroid gland regulates your body's metabolic rate and temperature, there are numerous other factors that influence your BBT, including hormones, stress, physical exertion, illness, medications, and the environment.

While some alternative therapists endorse the use of BBT to manage thyroid disease, the results rarely correspond to hormone levels, the development of symptoms, or your response to treatment. It is far safer to rely on the standard battery of tests, like the TSH and free thyroxine (T4), to gauge your thyroid function.


  • All goiters are caused by iron deficiency.


  • In the United States, Hashimoto's disease and Graves' disease are the most likely culprits.

A goiter is an abnormal enlargement of the thyroid gland and one of the symptoms people typically associate with thyroid disease. In the United States, goiters affect as many as 26 percent of women between the ages of 49 and 58 and 7 percent of men over age 60.

Globally speaking, iodine deficiency is the primary cause of goiter, mainly in developing countries where as many as 80 percent of the country's poor will be affected. However, that is rarely the case in the United States.

Though goiters are often associated with hypothyroidism, they can also occur with hyperthyroidism. In fact, the two most common causes in the United States are Hashimoto's disease and Graves' disease, both of which can cause thyroid enlargement in different ways. Other risk factors include smoking and obesity.


  • A lump in your thyroid means that you have thyroid cancer or are an increased risk of developing cancer.


  • The majority of thyroid nodules aren't cancerous and never will be.

The most common sign of thyroid cancer is a lump or nodule in your thyroid gland. While the appearance of a lump can be understandably distressing, up to 97 percent of cases will be entirely benign. This is especially true in people with hypothyroidism or a solitary thyroid nodule. Neither of these conditions is associated with an increased cancer risk.

By contrast, there is an increased risk among those with hyperthyroidism who develop multinodular goiters. A study published in the Journal of the American College of Surgery, which reviewed the medical data of 1,523 people who had undergone thyroid surgery, concluded that this subset of patients has an 18 percent increased risk of thyroid cancer compared to the general population.

Interestingly, while men are less likely to have goiters than women, they are statistically more likely to develop thyroid cancer.

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