[by Tamara Sellman RPSGT CCSH for Advanced Cardiovascular Sleep Disorders Center]
If getting eight hours of sleep a night is healthy, won't sleeping more than nine be even better?
The National Sleep Foundation recommends that most adults between the ages of 18 and 65 sleep between seven and nine hours a night for optimum health.
For adults age 65 and older, the recommendation is between seven and eight hours nightly.
They put a cap on the top number of hours of sleep on purpose. That's because sleeping too much is generally seen as unhealthy.
How can too much sleep be unhealthy?
In more general terms, too much sleep can lead to the following problems:
Cognitive fog: You awaken feeling foggy, and may struggle with concentration, focus, even memory issues.
Exacerbation of pre-existing chronic conditions: Too much sleep can lead to elevated levels of inflammatory substances, known as cytokines, in the bloodstream. When you have an ongoing increase in these inflammatory agents, that is referred to as chronic or systemic inflammation.
For those with disorders that are a product of system inflammation, long sleep can lead to flareups, such as is the case for those with arthritis, celiac disease, migraine, multiple sclerosis, and other conditions known to be caused by inflammation.
More pain: Your perception of pain can be heightened by a lack of sleep, but when you have too much sleep, you can end up with physical pain in the neck, shoulders, back, or hips.
Some people also experience something known as a "weekend headache," which could be linked to the inertia of the body and confused circadian rhythms that occur after you opt to sleep long.
Weight gain: Sleeping beyond the recommended guidelines can mess with the biochemistry in your brain, which is linked to light exposure and circadian rhythms. You may end up with confused appetite and stress hormones, which can lead to poor eating habits and a disrupted metabolism.
Together, these can lead to unwanted weight gain, especially if you're not physically active to begin with. Obesity is a common outcome of poor sleep.
Shortened lifespan: Sleeping for too long seems to point to dysfunction of the immune system, a reduction in daily exercise, evidence of broken sleep, and the emergence of daytime fatigue. All of these problems are linked to a higher mortality rate overall.
Hypertension: If you don't sleep enough, or sleep too much, this can elevate your chances for developing high blood pressure.
Chronic illness and too much sleep
If you routinely sleep more than the recommended hours a night for your age group, you might be setting yourself up for future problems with chronic disease.
Too much sleep can lead to problems with one's ability to metabolize (or tolerate) glucose (blood sugar) appropriately.
When impaired glucose tolerance occurs every night, and you sleep longer than nine hours, you might be sleeping your way to a condition known as insulin resistance--a risk factor for developing both type 2 diabetes and heart disease.
Besides experiencing insulin resistance, those who sleep too long have been shown to experience a higher risk for cardiovascular disease.
Heart conditions that are common to people who sleep too much include coronary heart disease, angina, chest palpitations, and a cerebrovascular accident (CVA, or stroke).
For the 65-and-older population, overlong sleep may hasten the development of Alzheimer's disease and other forms of dementia. This is because an overslept brain will function less efficiently, leading to dysfunctional at the cellular level.
One doesn't have to be a certified senior for this to take place; people in their mid-life years who suddenly start sleeping well over 9 hours a night might be encouraging poor brain health by doing so.
Studies suggest that women who are trying to become pregnant have much better odds if they sleep between seven and eight hours a night.
Other reasons you might be oversleeping
Maybe you need it. Getting in a couple of extra hours after a surgical procedure, a stressful experience, a sudden illness, or a string of poor nights of sleep is your body's way of letting you know you have sleep debt. It's not the random and singular need for extra sleep that should concern you, however, but the ongoing schedule that remains over nine hours a night.
An undetected sleep disorder
If your general pattern is to sleep over nine hours nightly, and you are still drowsy or feeling low energy or fatigue during the day, you might have a sleep disorder you're unaware of.
Some of the most common culprits?
- snoring and upper airway resistance
- central or obstructive sleep apnea
- periodic limb movement disorder (PLMD)
- insomnia and "painsomnia"
- sleep phase disorders (advanced or delayed)
All of these sleep problems can result in sleep fragmentation.
What is sleep fragmentation?
The best sleep is a consolidated process that takes place without interruption.
You shouldn't ever need to wake up in the middle of the night for any reason (not even to go to the bathroom). When this happens, our sleep architecture (the phases and stages of sleep) is fragmented by complete awakenings and arousals from deeper sleep to lighter sleep.
Certain important functions of sleep, such as hormone release, or memory consolidation, cannot take place if the process is constantly disrupted. Still, our brains and bodies need these functions fulfilled every night.
People who are depressed tend to sleep longer, according to research. And those who aren't depressed, who allow themselves to sleep longer than what is recommended for them, may find they are waking up irritable and lethargic. It becomes a vicious cycle, then. Feeling terrible can disrupt mood and cause oversleeping, which only perpetuates feelings of low energy and dampened spirits.
Much of the problem is due to a lack of synchronicity with one's circadian rhythms. The seven-to-nine-hour recommendation is based on well-established research that suggests human circadian rhythms require sleep at or around seven to nine hours a night.
To under- or oversleep can lead to circadian rhythm sleep disorders, including seasonal affective disorder (SAD), which combines a mood disorder with a sleep disorder inspired by the low light of the winter months.
Other side effects of daytime fatigue can include poor eating habits (stress eating or making unhealthy food choices) as well as poor sleep hygiene. Being vigilant about a consistent sleep schedule that doesn't exceed nine hours a night can do wonders for those who have fallen into a funk.
Poor Sleep hygiene
If you go to bed and awaken every single sleep period at widely varying times, you might be creating conditions for too much sleep.
People who choose to go to bed at distinctly different times due to social occasions, video game sessions, procrastinated homework, television binge-watching, or other voluntary activities that keep them up at night can easily fix this problem in schedule inconsistency. It will require that they prioritize sleep, which might mean cutting back on these events and other sleep disrupters.
For those who work night or graveyard shifts, a conscious effort to defend against shift work disorder is highly recommended.
What about naps?
Naps are a situation where there's both good news and bad news.
A random, planned nap to refresh oneself is not, by itself, a bad thing. However, regular naps to recover from daytime fatigue may be the sign of a more serious health problem.
Also, daytime napping for longer periods (two to three hours) can interrupt one's circadian rhythms and lead to sleep onset insomnia.
Make sure you nap only when you really need to, and keep your shut-eye session short (under 30 minutes) for best results.
How much sleep is just right?
- For adults ages 18 to 64, seven to nine hours is the healthy range. Strive to achieve it for the majority of your nights.
- For adults 65 and older, it's considered healthy to sleep seven to eight hours a night.
If you're concerned about frequent patterns of sleeping longer than these recommendations, please discuss your concerns with your primary care physician. They should be able to help you identify the reasons why you might be sleeping too long, and help you correct these problems.
Sources for further reading