Medically reviewed by
Dr. Katie Rothwell, ND, a licensed Naturopathic Doctor with clinical focus in thyroid conditions and Hashimoto's disease through The College of Naturopaths of Ontario, Canada
The thyroid, a small butterfly-shaped gland that sits at the base of the neck, produces hormones that mediate vital physiological processes such as metabolism, digestion, heart rate, brain function, and growth. Abnormalities with the production of these hormones are typical hallmarks of a defective thyroid.
When this happens, many key biological processes all over the body are negatively impacted, resulting in a host of conditions as presented by the symptoms of hypothyroidism (fatigue, cold intolerance, hair loss, constipation, and others) and hyperthyroidism (muscle weakness, heat intolerance, nervousness, diarrhea, and others). Thyroid disorders, such as hypothyroidism and hyperthyroidism, can disrupt the body’s sleep patterns and cause various sleep-related problems.
Sleep is regulated by the body’s 24-hour internal cycle of physical, mental, and behavioral changes known as the circadian rhythm. This 24-hour clock, controlled by a small structure in the brain known as the suprachiasmatic nucleus, is responsible for regulating a host of physiological processes such as body temperature regulation, hormone secretion, and the sleep-wake cycle.
The human sleep-wake cycle is regulated by a couple of hormones, including thyrotropin, also known as the thyroid-stimulating hormone (TSH). High TSH levels, usually indicative of hypothyroidism, suppress sleep and concomitantly promote wakefulness, while low levels of TSH, usually indicative of hyperthyroidism, promote sleep and concomitantly suppress wakefulness. Hence, it can be inferred that there is an apparent link between the sleep-wake cycle and the functioning of the thyroid.
In case you’re wondering if this is a big deal, the answer is yes. Sleep is extremely necessary for us to go about our normal daily lives. It is so important that the average human spends about a third of their lifetime asleep. Among many other benefits, sleep enhances memory, reduces inflammation, lowers the risk of heart disease and weight gain, and boosts the immune system. Whether you’re living with a thyroid disorder or not, it is important to understand how your thyroid affects your sleep.
This article will address the following major questions:
- How is your thyroid affecting your sleep?
- What can you do to make it better?
How is your thyroid affecting your sleep?
While it is true that thyroid disorders can negatively impact your sleep, many other factors also affect sleep. Not all sleep problems are caused by thyroid disorders, and not all people with thyroid disorders will have sleep problems. It is best to discuss with your healthcare provider if you have trouble falling or staying asleep or facing other sleep-related problems.
To answer the question of how the thyroid affects sleep, we will approach the question from three perspectives: euthyroidism, hypothyroidism, and hyperthyroidism.
Euthyroidism
Unless a person has other underlying medical conditions, a normal-functioning thyroid should not cause sleep disruptions. When the thyroid functions normally with normal levels of TSH and thyroid hormone, it actually helps promote proper sleep. The thyroid gland is instrumental in the central nervous system’s role in regulating sleep. The thyroid gland helps maintain a healthy sleep-wake cycle by regulating the body’s circadian rhythm. Thyroid hormones regulate melatonin production, too. Melatonin, often called the “sleep hormone,” is produced by the pineal gland in the brain in response to darkness to promote sleep. Thyroid hormones also regulate the levels of neurotransmitters in the brain, such as serotonin (a precursor of melatonin) and dopamine, that control sleep.
Hypothyroidism
When thyroid hormone levels are low, as in hypothyroidism, the body’s metabolism and circadian rhythm are disrupted, resulting in sleep disturbances.
The following are some of the ways in which hypothyroidism significantly impacts sleep:
- Sleep apnea: A significant section of people with untreated hypothyroidism suffer from sleep apnea, a condition characterized by disrupted breathing during sleep, leading to snoring, gasping, and choking.
- Hypothyroid patients with enlarged thyroids glands (goiter) may have their airways obstructed by the swelling. Hypothyroidism may also cause damage to muscles and nerves needed for breathing. The disruption of continuous sleep by sleep apnea may result in daytime fatigue and hypersomnia.
- Hypersomnia: Hypothyroidism can make it harder to stay awake during the day and cause excessive daytime sleepiness or frequent urges to sleep during the day.
- Restless legs syndrome (RLS): Hypothyroidism can also cause RLS, a neurological disorder that causes an uncontrollable urge to move the legs, especially at night. This can lead to disrupted sleep and daytime fatigue.
- Sleep may be disrupted at night due to cold intolerance alongside joint or muscle pain. Some people with hypothyroidism may experience longer sleep onset (longer time to fall asleep) and shorter sleep duration.
Hyperthyroidism
Just like hypothyroidism, the exact mechanisms by which hyperthyroidism affects sleep are poorly understood. However, what is known so far is that generally, some effects of hyperthyroidism, such as increased metabolism, changes in the circadian rhythm, and negative psychological states like anxiety, play significant roles in sleep disorders.
The following are some of the ways in which hypothyroidism significantly impacts sleep:
- Insomnia: Hyperthyroidism can cause increased metabolism, resulting in difficulty falling or staying asleep. Such difficulty usually stems from muscle weakness, constant feelings of tiredness, nervousness, or irritability. Although people with hypothyroidism may experience insomnia, insomnia is associated more with hyperthyroidism than hypothyroidism.
- Sleep apnea: People with hyperthyroidism may also experience sleep apnea. Compared to hypothyroidism, the likelihood of hyperthyroidism causing sleep apnea seems less. Hyperthyroidism can cause weight loss, which can lead to a narrowing of the airway and increase the risk of sleep apnea.
- Nightmares during sleep or rare cases of night terrors (a type of parasomnia characterized by sudden, terrified outbursts during the night).
- Sleep may be disrupted due to heat sensitivity, night sweats, and frequent urination. Difficulty in going back to sleep after such disruptions may be a sign of sleep maintenance insomnia.
What can you do to improve the quality of your sleep?
Upon noticing some of the signs outlined above, seeking timely medical attention helps your doctor determine the underlying cause and put you on a suitable treatment plan.
If your sleep disorder is truly as a result of a thyroid condition, the best way to tackle this is to treat the underlying thyroid condition. For that to happen, you will first need a diagnosis if you are unaware of your thyroid problem in the first place. This is understandable, as thyroid disorders are not always easy to detect solely based on symptoms. Once diagnosed, treatment begins, with close monitoring and assessment of treatment outcomes by your doctor.
For hypothyroidism, levothyroxine is the standard treatment option. Treatment options for hyperthyroidism include antithyroid medication (such as methimazole) and radioactive iodine therapy to shrink the thyroid gland if necessary. You must also familiarize yourself with how to take your thyroid medication properly. More importantly, always follow your doctor’s prescription and advice.
Aside from all that, you may need to take extra measures to help improve your sleep. Most of these involve a suitable, calm environment, proper sleep hygiene, and a healthy diet.
The following are some measures to help mitigate sleep disruptions.
- Ensure you have optimal bedroom temperature. This helps prevent you from feeling too hot or cold to have undisrupted sleep.
- Before sleeping, make use of relaxing activities such as bathing, reading, and music. Some people find that sleeping with quiet relaxing music helps them relax and sleep better. If you’re such a person, you can make that a routine once you observe some improvements in the duration and quality of your sleep.
- Follow a consistent bedtime routine. Going to bed and waking up at the same time every day helps with the consistency of your sleep cycles and entire circadian rhythm.
- Avoid excessive lights before going to bed. This means you should stay away from gadgets like phones or computers for about an hour or two before sleeping.
- Avoid heavy meals before bed. Light snacks may be ideal, depending on how soon you sleep after taking them.
- Avoid excessive iodine intake. Make sure your diet always has just about the required amount of iodine. Too much iodine affects thyroid activity.
- Caffeine, nicotine, and alcohol shortly before bed also affect sleep. Limit your consumption of these, or avoid them altogether, if possible.
Key Takeaways
- A normally functioning thyroid promotes sleep through the regulation of metabolism, melatonin production, neurotransmitter activity, and circadian rhythm.
- A defective thyroid gland is ultimately capable of affecting one’s brain function and overall physical health.
- An overactive or underactive thyroid and abnormal TSH levels increase the risk for sleep disorders.
- Thyroid disorders such as hypothyroidism and hyperthyroidism can be considered risk factors of some sleep disorders.
- Thyroid disorders do not only affect sleep duration, but the overall quality of sleep.
- Thyroid disorders can cause sleep apnea, a condition where breathing is repeatedly interrupted during sleep. Sleep apnea can lead to daytime sleepiness, fatigue, and other health problems.
- Not all sleep problems are caused by thyroid disorders, and not all people with thyroid disorders will have sleep problems.
- Symptoms of hypothyroidism and hyperthyroidism tend to overlap sometimes. Similarly, there is also an overlap between some of the manifestations of the effect of an overactive thyroid gland on sleep.
- If you’re experiencing sleep disturbances and have other symptoms of thyroid dysfunction, such as fatigue, weight changes, or changes in mood, it is important to discuss this with your healthcare provider to determine the underlying cause of your symptoms.
- Besides treating your underlying thyroid condition, it is also important to take key measures to enhance the overall quality of your sleep.
- Ensure that you have a suitable, calm sleeping environment, maintain proper sleep hygiene and practice good eating habits, and maintain a healthy diet.
