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The thyroid is a small gland in the endocrine system which helps control our metabolism. Thirteen million Americans suffer from disorders of the thyroid, making these potentially serious conditions a common complaint.
Thyroid disorders also have a unique relationship with sleep and sleep dysfunction. Not only do they each affect your sleep health in different ways, but they can also increase your risk of sleep disorders like sleep apnea, and may even influence your circadian rhythm.
For this article, we have investigated the science behind the thyroid-sleep connection, explored the most common types of thyroid disorders, and gathered together relevant sleep health advice. Keep reading to learn more and discover your options.
Just beneath your voice box is a small, butterfly-shaped gland called the thyroid. Despite weighing less than an ounce, your thyroid plays a vital role in the normal functioning of your body.
As part of your hormonal endocrine system (other major endocrine organs include the pituitary gland, adrenal glands, pancreas, and reproductive organs like testicles and ovaries), your thyroid helps regulate your metabolism. Your entire body is affected by the proper production, storage, and release of three essential thyroid hormones:
Both T3 and T4 are created using iodine. In areas where iodized salt is uncommon, thyroid disorders are often caused by an iodine deficiency, but this is less of a concern in America.
Your thyroid manipulates your metabolism using these hormones, particularly T3 and T4. Since both increase your metabolic rate, maintaining your metabolism is a complicated balancing act which can be quickly thrown off-balance by a problem with your thyroid.
If you are concerned that you may have a thyroid disorder, please speak to your doctor. Most thyroid problems can be diagnosed and treated by a primary care physician, but you may be referred to an endocrinologist as well.
Not all problems with your thyroid are an immediate concern. If you have abnormal hormone levels when tested, but the levels are beneath a threshold and you have few or no symptoms, you may have what is called a “subclinical” disorder. Your doctor will discuss your options, which may or may not include treatment.
Hypothyroidism, or low thyroid hormone production, is the most common thyroid disorder. Sufferers, a majority of them women, make up 80% of the estimated thirteen million Americans with thyroid disease. Rates also rise with age, so that 20% of women over the age of 65 are suspected of having a hypoactive thyroid.
As the disorder progresses, a range of symptoms may appear or change:
|Initial Symptoms||Later Symptoms|
|Joint and muscle pain, weakness||A hoarse voice|
|Fatigue despite sleeping more than usual||Swollen face, hands, or feet|
|Increased sensitivity to cold||Slow speech|
|Weight gain||Thin or brittle eyebrows, hair, and nails|
|Depression, anxiety||Decreased senses of taste and smell|
|Heavy menstrual periods||Thickening skin|
We know that shift workers have a higher risk of hypothyroidism, but this link between the disorder and sleep dysfunction is still being researched. There are three primary causes for hypothyroidism: autoimmune disorders, secondary hypothyroidism (caused by a dysfunctional pituitary gland), and congenital hypothyroidism which is present from infancy.
All can be treated, reducing the greater risk of heart problems, high cholesterol, and high blood pressure in hypothyroid patients.
On the opposite end of the scale, hyperthyroidism (also called thyrotoxicosis) is the excessive production of thyroid hormones.
While rarer than hypothyroidism — approximately 1-3% of Americans have the disorder, which is more common in women — hyperthyroidism can result from many different causes. These include autoimmune disorders like Grave’s Disease, infection, pregnancy, goiters or nodules (see below), and other issues.
Symptoms of the disorder vary between individuals, but the most common are:
Effective treatment for hyperthyroidism is available but will depend on what is causing the elevated hormone levels.
Thyroiditis is a form of thyroid inflammation caused by the immune system. Viral and bacterial infections can be the root of the problem, as can some other conditions.
The most common form is Hashimoto’s thyroiditis, an autoimmune disease which causes your body to attack the cells in your thyroid. Over time, the thyroid begins to feel “firm” and “rubbery”, and will stop producing enough thyroid hormones.
Postpartum thyroiditis is similar to Hashimoto’s thyroiditis but occurs in the months following childbirth. It usually begins with symptoms of hyperthyroidism before sufferers become hypothyroid, making it difficult for some people to notice a pattern.
In fact, this progression — from hyperthyroidism to hypothyroidism — is typical in most thyroiditis. If you are exhibiting symptoms of both conditions, thyroiditis may be behind your concerns.
Your thyroid can become enlarged (goiter) or develop lumps or masses (called nodules). Although alarming, goiter and nodules are both common, respond well to treatment, and usually do not seriously affect your health.
Goiter comes in two forms: diffuse goiter, which describes a smooth, generalized enlargement, and nodular goiter, which occurs due to the enlargement of separate nodules or lumps. Your thyroid might keep producing the right amount of hormones (called a nontoxic goiter) or develop into hypo or hyperthyroidism.
Nodules can be malignant (see Thyroid Cancer below) but are usually benign. These common masses occur in 6% of adult women and 2% of adult men, but it is thought that up to one-third of women and one-fifth of men might have smaller versions.
Treatment may or may not be needed for benign goiter or nodules. Your doctor will explain the underlying causes and discuss your options.
Cancer of the thyroid is uncommon, affecting approximately 14.5 people in America out of every 100,000 individuals. Although there is still much research to be done on the causes of thyroid cancer, the primary risks we know of are exposure to radiation (particularly at a young age) and genetic factors.
One study also found that insomnia may be a risk factor. While more research is needed to develop this line of inquiry, it poses intriguing questions about the connection between sleep and thyroid disorders.
Some symptoms of thyroid cancer mimic hypothyroidism, but others include:
Treatment usually consists of surgery, radioactive iodine, and radiation.
Thyroid hormones, particularly T3 and T4, help control your metabolism. When you have low levels of these hormones, the drop in your metabolism causes your body to slow down. This slowdown affects your entire body, making you feel sluggish, cold, and tired. You sleep for more hours but feel worse.
Another potential cause for thyroid-related hypersomnia is that hypothyroidism may disrupt slow-wave sleep. Also known as stage 3 or deep non-REM sleep, this sleep stage contains the sleep we describe as “refreshing” and is what resets our feelings of sleepiness. If hypothyroidism does restrict stage 3 sleep in some way, it would explain the persistence of hypersomnia in sufferers.
The sleepiness and exhaustion caused by hypersomnia are not alleviated by daytime naps. No matter how much sleep they achieve at night or how often they nap, sufferers remain exhausted. Some find it very difficult to wake up in the morning, disturbing their circadian rhythm and further disrupting their sleep.
In addition to having a negative impact on quality of life, this excessive daytime sleepiness can also be dangerous. For example, driving drowsy is more dangerous than driving drunk, and was responsible for 44,000 accidents and 800 deaths in 2013 alone.
Thankfully, successful treatment of a hypoactive thyroid usually eliminates fatigue and hypersomnia over time.
Just as low levels of thyroid hormones can cause hypersomnia, the high levels found in people with hyperactive thyroids can cause insomnia.
Experts suggest that adults need six to nine hours of sleep per night, with seven to seven and a half hours being the sweet spot for most people. Insomnia, which can take the form of either struggling to fall asleep or stay asleep, prevents people from achieving the sleep they need.
Hyperthyroidism encourages insomnia in two primary ways:
Like hypersomnia, insomnia can also result in extreme tiredness — in this case, sleepiness — which lowers your quality of life and increases the risks associated with sleep loss.
If you are suffering from insomnia which you suspect may be due to a thyroid disorder, consider keeping a sleep diary. This will give you and your care team a more in-depth insight into whether you have trouble falling or staying asleep, whether your insomnia is primarily caused by physical or mental symptoms, and other important factors. Not only will it potentially help treat your insomnia, but it may also provide information on your thyroid disorder.
Obstructive sleep apnea, also known as sleep apnea, is a common sleep breathing disorder affecting 3-7% of American men and 2-5% of American women. Sufferers stop breathing multiple times a night when their throat tissue and muscles relax and block their airflow. Snoring occurs from muscle and tissue vibration, blood oxygen levels decrease, and eventually, they wake up to breathe again (whether they are aware of the awakening or not).
The relationship between sleep apnea and hypothyroidism is complex. On one level, having a hypoactive thyroid increases your risk for sleep apnea. There are many possible reasons for this increased risk, including respiratory changes, nerve or muscle damage, chemical imbalance, and even enlargement of the tongue.
On another level, distinguishing between sleep apnea and hypothyroidism can often be difficult for primary care physicians. The two conditions share many symptoms, such as fatigue and mood changes, and both are relatively common.
In fact, there is an ongoing controversy in the medical community about whether to test for both when symptoms occur. For example, in one study of individuals with suspected sleep apnea, 47% were diagnosed with Hashimoto’s thyroiditis, a common cause of hypothyroidism.
If you suspect you may have either or both hypothyroidism and sleep apnea, your doctor may refer you for tests. Sleep apnea is diagnosed by studying your sleep, while hypothyroid diagnosis involves testing your levels of TSH and thyroid hormones.
Approximately 1-15% of people will experience restless leg syndrome (also known as Ekbom’s syndrome, Willis-Ekbom disease, or RLS) in their life. This movement disorder creates an uncomfortable and overwhelming urge to move your legs, particularly at night or when you are lying down. While movement temporarily relieves these feelings, the relief is short-lasting, and the sensations return.
RLS is more than just a minor irritation. The condition raises the risk of heart disease in older women just as much as other risks like smoking and obesity, partially because of the significant impact it can have on how much sleep you achieve.
Abnormalities in the regulation of neurotransmitters, hormones, and nutrients are known to cause RLS, and research indicates that thyroid-stimulating hormone (TSH) may be related to the condition as well. One of the compounds which regulates TSH has been shown to alleviate RLS symptoms, and conditions with high levels of thyroid hormones create a higher risk of developing RLS.
There is a hypothesis that age may also play a factor in the link between RLS and thyroid disorders. Older people metabolize thyroid hormones more slowly than younger people, and they are also 2% more likely to have hyperthyroidism. It is possible that this age-related change to thyroid hormone levels creates a higher risk of RLS as well.
Regardless of its cause, RLS (thyroid-associated or otherwise) can be treated. Severe cases may require medication, but mild to moderate cases often respond well to lifestyle changes and good sleep hygiene (see “Practice Good Sleep Hygiene” below). Treatment of your thyroid disorder may also lead to RLS improvement.
Circadian rhythms describe the normal cycles of your biological processes. These rhythms not only control when you fall asleep and wake up, but they also control short and long-term cycles of everything from your heartbeat to hormone production.
As part of the endocrine system which regulates hormones, your thyroid is influenced by your circadian rhythms. Studies have shown that the hormone which prompts the release of thyroid hormones (TSH) has a circadian profile, as do the T3 and T4 thyroid hormones. Levels of these are usually higher at night, rather than when we are awake.
This is particularly interesting, as one hormone — melatonin — rises at night as part of the circadian system to help us sleep, but also shows a suppressive effect on thyroid function in some studies.
Produced by the pineal gland in the brain (which is part of the endocrine system and controls the production of TSH), melatonin is well-known as a supplemental sleep aid. However, rats who were given melatonin injections had decreased levels of both TSH and thyroid hormones, while fetal hamsters showed slowed thyroid growth.
Given these studies, it seems unusual that melatonin and thyroid hormone levels both naturally rise at night without the melatonin affecting thyroid function. Further studies are needed, and it may be that supplemental melatonin has an effect whereas natural levels do not.
In some cases, melatonin’s suppressive effect can be useful. There have been some studies which show that melatonin may be useful as a treatment for thyroid cancer due to its ability to slow tumor growth there.
Overall, the research into melatonin and thyroid function is just beginning. However, it does give us a new way to approach the sleep-thyroid connection and offers an exciting direction for further research.
Untreated thyroid disorders can be severe, but treatment is available through your doctor or endocrinologist. The treatments vary depending on which disorder you suffer from, but these are the four most common:
|Synthetic hormones||Patients with a hypoactive thyroid, or those who have had their thyroid removed, are prescribed synthetic thyroid hormones.|
|Beta blockers||Beta blockers are used to block the effects of thyroid hormones in hyperthyroid patients.|
|Radioactive Iodine||Taken in the form of a pill or liquid, radioactive iodine slowly destroys portions of the thyroid. It is used for thyroid cancer and hyperthyroidism.|
|Surgery||Surgery is rarely necessary for benign goiter or nodules but may be used if a patient is having trouble breathing or eating. It is also used for thyroid cancer and some cases of hyperthyroidism.|
All treatment options come with their own range of side effects, which your care team will help you avoid where possible. However, most chronic thyroid dysfunction can be successfully treated to the point where regular testing of hormone levels is the only long-term effect on your quality of life.
Your doctor may also suggest lifestyle changes to alleviate thyroid disorder symptoms until the root cause can be treated. For example, hyperthyroid patients who struggle with racing thoughts and anxiety may benefit from meditation (see below).
Finally, remember to take care of your mental health as well as your physical health. Mood and anxiety disorders are common in thyroid patients, with depression and anxiety appearing as symptoms of thyroid dysfunction. Not only will this improve your quality of life, but it will also help you sleep better.
Your bedtime habits, rituals, and behaviors are called sleep hygiene. By creating a positive sleep routine you can follow nightly, you will ensure you are practicing good sleep hygiene.
Where you sleep is important to everyone, but people with thyroid disorders have specific needs from their bedroom. Whether you have hypothyroidism and tend to feel cold and depressed, or you have a hyperactive thyroid and are warm all the time, creating the right sleep space is key to a good night of sleep.
We sleep better in cooler temperatures, and for most people the ideal temperature for falling asleep is between 60 and 67 degrees Fahrenheit. (Warm baths can help with sleep partially because the evaporating water and temperature change make you feel cooler afterward.) If you regularly find your bedroom too hot or too cool, consider making changes with an air conditioner or extra blankets.
Darkness and silence are also crucial elements of a functional sleep space. Small electronic lights, street light from outside, traffic, the snoring of a partner: all of these can make falling asleep an ordeal. Achieve darkness by banishing electronics and purchasing blackout curtains if necessary, then pick up earplugs, sleep headphones, or a white noise machine to counteract sound pollution.
The last step in preparing your bedroom is removing all distractions. Bedrooms should ideally only be used for sleeping and sex, so consider moving any televisions or other devices elsewhere in your home.
Meditation, yoga, and mindfulness techniques are all powerful tools. While considered alternative therapies, research has shown their efficacy in improving both mental and sleep health. There is also a growing interest in discovering whether they may be useful in treating thyroid disease, though research on the subject is currently lacking.
Many studies on relaxation techniques emphasize the importance of mindfulness. This secular approach has roots in Buddhist philosophy and focuses on maintaining an awareness of your self, breath, body, and environment with gentle acceptance. Mindfulness meditation classes are likely available near you, or you can learn about the practice online.
Studies have shown that mindfulness meditation improves insomnia and sleep dysfunction, as well as the depression and fatigue which often accompany sleep problems. By making the practice part of your sleep routine, you may be able to help alleviate the effects of your thyroid disorder on your sleep.
As both a form of exercise and a way of meditating, yoga has also shown itself to be useful in treating sleep problems. Over 55% of yoga practitioners find it helps them sleep, which has been backed up by studies which found it to be useful.
If you do decide to use alternative therapies like relaxation techniques, speak to your doctor first. This will offer them the best view of your current situation and allow them to answer any questions you may have.
We hope this article has helped shed light on both thyroid conditions and sleep itself, as well as offering tools you can use to improve your sleep health.
Thyroid disorders can be overwhelming, particularly if you aren’t getting enough high-quality sleep. However, medical treatment and lifestyle changes can have a positive effect on your sleep, quality of life, and health.
The importance of sleep is common knowledge, but do you know the effects of sleep dysfunction and the best ways to achieve better sleep? Follow the links below to learn more about the science of great sleep.