The Link Between Hypothyroid and Sleep Apnea

The thyroid plays a key role in producing hormones that help regulate body functions including heart rate, body temperature, and metabolism.

If these hormones are not produced in sufficient quantities, it can lead to an imbalance that may affect the quality of your sleep. This can lead to the development of sleep disorders -- one link being between hyperthyroid and sleep apnea.

Hypothyroidism

When your thyroid is producing insufficient levels of the hormone thyroxine, it is termed hypothyroidism. There can be a gradual intensification of the symptoms. One of the main effects of the condition is to slow your metabolism.
Some of the initial signs of hypothyroidism are:

  • fatigue
  • daytime sleepiness
  • increased sensitivity to the cold
  • joint or muscle pain

Without correcting the hormone levels produced by the thyroid, further symptoms can begin to show as your metabolism continues to slow.

  • weight gain
  • puffy face
  • dry skin
  • constipation
  • hoarse voice

How Your Thyroid Impacts the Quality of Your Sleep

The chemical imbalance resulting from reduced levels of hormones produced by the thyroid can impact your circadian rhythm. This is your body clock that regulates your sleep/wake cycle. 

Someone with hypothyroidism can find it difficult to fall asleep and to stay asleep. This can see them develop or worsen sleep disorders such as insomnia or obstructive sleep apnea.

The Link Between Hypothyroid and Sleep Apnea

Obstructive sleep apnea is the most common form of sleep apnea. You briefly awake, gasping for air numerous times every hour, depending on the severity of the disorder. This is triggered by a blockage of the airways as the throat muscles relax when you sleep. The drop in blood oxygen levels is detected by the brain, which prompts the body to wake for air.

Although there is not a direct link to obstructive sleep apnea, having hypothyroidism can increase your risk of such a sleep disorder. This is because the symptoms and effects of hypothyroidism can negatively affect the quality of your sleep. 

The following are ways in which hypothyroidism may contribute to or worsen obstructive sleep apnea:

  • joint or muscle pain can make sleeping difficult
  • increased sensitivity to cold temperatures can impact sleep
  • an enlarged thyroid gland due to hypothyroidism may obstruct the airway as the gland sits at the base of the windpipe
  • weight gain can lead to more throat muscle tissue pulled down by gravity as you sleep to obstruct the airways
  • weakened muscles can make it harder to breathe correctly through the night

Therefore, while hypothyroidism may not be a direct cause of obstructive sleep apnea, it can create the conditions that increase your chance of developing the disorder. 

When your thyroid is not producing enough of the hormones the body needs, it can impact sleep quality and lay the foundations for developing a sleep disorder like sleep apnea.

Treatment Options

Both hypothyroidism and sleep apnea can be treated and managed once diagnosed. The issue can be the possibility that sleep apnea is overlooked as some of the symptoms like daytime fatigue are similar to the effects of hypothyroidism.

A blood test can detect whether your thyroid is producing sufficient levels of hormones. If it is not, then you can be prescribed medication to help normalize the levels. Your doctor will base the level of medication on factors such as your age, but with the correct dosage, you should see most of the symptoms of hypothyroidism gradually go away.

A tell-tale sign that you may also have sleep apnea is if you still experience daytime sleepiness while on medication to treat hypothyroidism. Further signs of obstructive sleep apnea include:

  • frequent awakenings at night, sometimes gasping for air
  • loud snoring
  • morning headaches
  • dry mouth in the morning
  • poor concentration
  • irritability

It can often be a partner who first notices your breathing difficulties while you are sleeping. If you recognize any of the signs of sleep apnea, you should consult with your doctor who can arrange a sleep study. This can either be done using an at-home test kit or through an overnight stay at a sleep clinic where your sleep patterns will be monitored.

One of the leading treatments for obstructive sleep apnea is PAP therapy which stands for positive airway pressure. This uses a device that delivers pressurized air through tubing to a mask worn overnight to keep the airways free of obstruction. PAP therapy can soon restore good quality sleep.

The two conditions should be treated individually. If diagnosed with both conditions there is not yet any available evidence to suggest that just treating hypothyroidism on its own will reduce the number of micro-arousals caused by untreated sleep apnea. On the plus side, diagnosis followed by treatment of both conditions can benefit your overall symptoms.

Good Sleep Health

Aside from prescribed treatments, adapting routines and methods that encourage sleep can improve overall sleep quality if you have an issue with your thyroid. This includes:

  • a bedtime routine where you go to bed at the same time each night and rise at the same time each morning
  • relaxing pre-bed activities like reading, meditation, or having a bath
  • a dark bedroom with a comfortable temperature, not too hot and not too cold
  • reduced alcohol and caffeine consumption
  • quitting smoking
  • avoiding large meals close to bedtime
  • regular exercise, although not too close to bedtime
  • consulting with your doctor on measures to manage any stress or anxiety affecting your sleep

Final Thoughts

The link between hypothyroid and sleep apnea is strong, as many people with hypothyroidism are also diagnosed with sleep apnea. The symptoms of hypothyroidism can impair sleep -- and a reason why you are at an increased risk of being diagnosed with a sleep disorder. However, treating both conditions can prove beneficial in improving your overall symptoms.

Sources:

https://www.webmd.com/sleep-disorders/thyroid-and-insomnia 

https://www.medicalnewstoday.com/articles/hypothyroidism-and-insomnia#indirect-effects