Myths about Sleep

The National Sleep Foundation concluded in a 2002 study that "while many Americans enjoy the benefits of sufficient sleep, as many as 47 million adults may be putting themselves at risk for injury, health and behavior problems because they aren't meeting their minimum sleep need." The National Sleep Foundation describes some common myths about sleep:

Myth: You can “cheat” on the amount of sleep you get.
Sleep experts say most adults need between seven and nine hours of sleep each night for optimum performance, health and safety. When we don’t get adequate sleep, we accumulate a sleep debt that can be difficult to "pay back" if it becomes too big. The resulting sleep deprivation has been linked to numerous health problems.

Myth: The older you get the few hours of sleep you need.
Sleep need remains unchanged throughout adulthood. Older people may wake more frequently through the night and may sleep less, but their sleep need is no less than during young adulthood. When older people sleep less at night, they tend to sleep more during the day. Sleep difficulties are not a normal part of aging, although they are all too common.

Myth: Sleep disorders are mainly due to worry or psychological problems.
Stress is the number one reason people report insomnia. However, stress accounts for only a fraction of the people who suffer either chronic insomnia or difficulty staying alert during the day. Sleep disorders have a variety of causes. And there are different types of sleep disorders which are physical health problems, such as sleep apnea, narcolepsy, and others. Most sleep disorders are health conditions which can be treated. Untreated sleep disorders may have serious negative effects, worsening quality of life, school and work performance, and relationships. Worse, untreated sleep disorders may lead to accidents and death.

Myth: Snoring is not harmful as long as it doesn't disturb others or wake you up.
Although snoring may be harmless for most people, it can be a symptom of a life threatening sleep disorder called sleep apnea, especially if it is accompanied by severe daytime sleepiness. Sleep apnea is characterized by pauses in breathing that prevent air from flowing into or out of a sleeping person’s airways. People with sleep apnea awaken frequently during the night gasping for breath. The breathing pauses reduce blood oxygen levels, can strain the heart and cardiovascular system, and increase the risk of cardiovascular disease, stroke and heart attack. Yet 95% of those with sleep apnea remain unaware that they have a serious disorder. The good news is there is treatment.

Myth: “I can tell when I’m going to go to sleep.”
If you're like most people, you believe you can control your sleep. In a test, nearly four-fifths of people said they could predict when they were about to fall asleep. They were wrong. The truth is, sleep is not voluntary. If you're drowsy, you can fall asleep and never even know it. You also cannot tell how long you've been asleep. When you're driving, being asleep for even a few seconds can kill you or someone else.

The cycle of apnea:

The apneic patient falls asleep

Muscle tone in the body relaxes

Airway narrows and/or collapses, causing breathing to be difficult or impossible.

The collapse of the airway may cause loud snoring, snorts, pauses in airflow, and labored breathing

Oxygen levels begins to fall.

The apneic patient continues to struggle for breath…time goes by…10, 20, 40 seconds…and longer…

Heart rate falls below normal—there is decreased oxygen to pump through the body.

Brain senses low oxygen/high carbon dioxide level, releases jolt of adrenaline—“fight or flight” response—to awaken brain and body and prevent suffocation.

Sleeper awakens briefly, takes five or six large breaths, breathing in oxygen and blowing off excess carbon dioxide (CO2). Sleeper typically does not remember arousal. Sleeper often repositions him or herself on the bed.

Heart rate speeds up in response to rush of adrenaline—now pumps above normal heart rate.

Oxygen/carbon dioxide levels return to near normal. Brain allows sleeper to resume sleeping.

Sleeper falls asleep.

Muscle tone relaxes…

Cycle repeats.


Sleep Apnea: Phantom of the Night

It is not unusual for an apneic patient to have over one hundred arousals per night due to apnea, though he or she most likely will not remember any of them. This makes apnea suffers—especially those who live alone or sleep in bedrooms separate from their partners—vulnerable to not having their condition diagnosed for many years, if ever.

Severity of sleep apnea is measured by three variables.

The number of apneic episodes per hour—also known as a respiratory disturbance index (RDI).
An RDI of 5-15/hr is considered mild sleep apnea.
An RDI of 16-30/hr is considered moderate sleep apnea.
An RDI of +30/hr is considered severe sleep apnea.
Levels of oxygen desaturation. Normal waking oxygen saturation in a healthy child or adult is 96-99%. Normal asleep oxygen saturation in a healthy child or adult is 94-98%.

Moogy wrote:According to my family practice doctor, when O2 drops below 80%, it actually kills off some brain cells, which cannot be replaced. Now, humans have a LOT of brain cells, so we can do without some of them, but still we don't want to be destroying them for no reason....
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Actually scientists have discovered lately that some brain cells CAN actually regenerate and therefore replace the dead ones. Quite an amazing discovery, as it reversed decades of thought that it wasnt possible. I'll try and locate some sources, as I've not only read it online but also seen on TV.

dsm wrote: I can imagine that lowered SpO2 means that the muscles etc+ are not getting good supplies of oxygen ' can suffer

I can also imagine that because sleep is a time when the body goes through maintenance & tissue repair/replacement, that lowered SpO2 can cause this process not to work as well as it needs to and thus can result in not feeling fit when one wakes up.