Fun Facts About Sleep, and 6 Common Infections We Wish Never Existed
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Fun Facts About Sleep By Ellen Ferry
On the outside, we look relaxed, peaceful, and unaware. But what goes on while we sleep? We spend nearly one-third of our lives—approximately 25 years—in a state of sleep, yet we remember little to none of it. When you hit the pillow, your body doesn’t turn off. It begins an intricate cycle of rejuvenation that is vital to your health and well-being. Read on to learn more about this thing that none of us can live without.
The Necessity of Sleep
Sleep researcher William Dement once claimed that the national sleep debt is a greater threat to the United States than the national monetary debt. Most people do not get an adequate amount of shuteye. In a 2009 poll, 20 percent of Americans reported getting less than six hours of sleep per night.
Why do we need sleep?
The answer seems obvious. Without it, we become walking zombies, propelled through the day by caffeine and weary determination alone. Though no definitive answers exist concerning its precise purpose, sleep is believed to help restore body tissues and assist in the growth process.
Circadian Rhythm
It’s Saturday morning—your one day to sleep in. To your dismay, you wake at the time your alarm normally goes off and have trouble getting back to sleep. That happens because your body is acting under its biological clock, or circadian rhythm (from the Latin circa, “about,” and dies, “day”). A region of your brain called the hypothalamus regulates your patterns of sleep and wakefulness, matching them to the 24-hour cycle of day and night. A person typically sleeps for 8 hours within that period and is awake for 16. Be careful—staying up unusually late or snoozing for too long can throw off your rhythm and necessitate a period of readjustment.
The Sleep Cycle
The process of sleep occurs in five distinct stages that repeat about every 90 minutes. When you first lay down to rest, your breathing rate slows as you transition from consciousness to a light sleep known as stage 1. After two minutes or so, you relax further, entering into stage 2 sleep. Your body temperature drops and breathing becomes regular during that 20-minute stage.
Stages 3 and 4— where sleepwalking and talking can occur—are deep, restorative forms of sleep characterized by large, slow brain waves. Together they last approximately 30 minutes. Before entering stage 5—an intriguing stage known as REM (rapid eye movement) sleep—you pass back through stages 3 and 2. Most people repeat that cycle several times before morning.
REM Sleep
REM sleep is the stage in which dreams occur. It is characterized by an accelerated heart rate, rapid and irregular breathing, and periods in which the eyes dart back and forth. Approximately 25 percent of the night is spent in REM sleep, and people will remember a dream more than 80 percent of the time if woken during a REM period. The average person spends nearly 600 hours dreaming each year during REM sleep.
REM Rebound
Though the precise function of REM sleep is fiercely debated, the fact that we need REM sleep is not. If frequently interrupted during sleep or deprived of it, our bodies will compensate by naturally passing more quickly through the non-REM stages of sleep (stages 1, 2, 3, and 4) into REM sleep, a phenomenon known as REM rebound. Humans are not the only ones who need REM sleep, as REM rebound has been observed in several other animals as well.
The Function of Dreams
The phenomenon of REM rebound suggests that dreams serve a purpose beyond mere entertainment. Several theories seek to explain the function of dreams. Psychologist Sigmund Freud—whose theories revolve around the concept of the “unconscious mind”—believed that dreams are a way for a person to harmlessly discharge repressed thoughts and desires.
A more recent theory suggests that dreams allow us to consolidate and arrange our memories, and yet another proposes that dreams serve the physiological purpose of preserving and maintaining neural pathways. Despite those ideas, other experts maintain that dreams are nothing but random meaningless bursts of brain activity.
Has a friend ever approached you excitedly and announced, “You’ll never believe what I dreamt last night!” If so, they likely followed with a vivid dream story that left you laughing or puzzled. Perhaps you have experienced a dream like that yourself. While fantastic dreams do occur—as well as the occasional nightmare—the majority of dreams are quite ordinary. We tend to relive typical day-to-day events in our dreams, and sometimes factors in our environment are incorporated into our dream story, such as a particular scent or, in an unfortunate case, the buzz of an alarm clock.
Insomnia: A Common Sleep Disorder
The most commonly reported sleep disorder is insomnia, experienced by approximately 10 to 15 percent of adults. Insomniacs report difficulties falling asleep or staying asleep. Some turn to sleeping pills or alcohol, but many natural alternatives have been established to assist with sleeplessness. Experts recommend regular exercise, a consistent sleep schedule, and a relaxing bedtime routine for those struggling with insomnia.
Hypnic Jerks
Something strange sometimes occurs between sleep stages 1 and 2. Perhaps you have experienced this phenomenon: just as you begin to drift off, your body jerks involuntarily, often in response to an abrupt sensation of falling. Such jolts are known as hypnic jerks or sleep starts. Experts insist that they are completely normal, but the reason for them is unclear. Some theorize that, as the muscles relax, the brain mistakenly registers that the body is falling and jolts to “catch” itself.
6 Common Infections We Wish Never Existed
The curation of this content is at the discretion of the author, and not necessarily reflective of the views of Encyclopaedia Britannica or its editorial staff. For the most accurate and up-to-date information, consult individual encyclopedia entries about the topics.
We all miss a day of school or work here and there thanks to a cold or a sore throat. But those maladies have nothing against the ones presented in this list—six afflictions that many of us have come to know all too well. And if by some miracle of hygiene, you’ve somehow managed to escape the awfulness of these unpleasant and disturbingly common infections, then brace yourself, because your luck is likely to run out.
An Awkward Silence: Chlamydia
Chlamydia is a classic silent disease. Most people who contract it are asymptomatic or experience only subtle (subclinical) symptoms. Those individuals, the “silent” carriers, are spared the various unpleasantries of Chlamydia bacterial infection, which range from purulent urethral discharge in men to pelvic inflammatory disease and ectopic pregnancy in women. But those individuals are them, guaranteeing more than a few moments of awkward silence when their condition is finally discovered, by which time long-term health consequences may have already set in.
Dermatophytes Feeding on My Keratin
From head to toe, every inch of skin on the human body is susceptible to invasion by dermatophytes, fungi that thrive on keratin, the major structural protein in our outer skin layers. In general, dermatophytes thrive in moist environments, with the scalp, the groin, and the toes being especially popular places of residence. Invasions in those parts of the human anatomy are responsible for scalp ringworm (tinea capitis), jock itch (tinea cruris), and athlete’s foot (tinea pedis), respectively. Dermatophytes can be transmitted from one person to another or from pets to people, and they can survive on towels, hairbrushes, clothes, and other objects.
A Sensation of Sand in the Eye
conjunctivitis
That gritty, grating feeling of bits of sand rubbing against the eyeballs is a common symptom of conjunctivitis, popularly known as pinkeye. It may be caused by allergens or other irritants, or by bacteria or viruses, with the latter two being responsible for the infectious form of the disease. Infectious conjunctivitis is exceedingly contagious. Even just sharing a towel or a swimming pool with a pinkeye victim is sufficient for the transmission of viral conjunctivitis.
Otitis Media: O(h)-titis, a Blight in the Ear
The sight of yellowish-green fluid seeping out of the ear is alarming, and in many cases, it is a symptom of one of the more common afflictions of childhood—otitis media, more commonly known as a middle ear infection. Drainage from the ears is an “ick” factor that compounds the awfulness of the fever and earache typically brought on by a middle ear infection. The condition may be caused by viruses or bacteria and it comes in various forms, though acute otitis media is the most common. About two-thirds of children have had an acute ear infection by age one and by age seven more than one-third have had an astonishing six or more episodes.
Bleeding Gums: Gingivitis
As I write, bacteria are working their way into your gums, if they aren’t there already, multiplying and contributing to the buildup of the yellowish film of plaque on your teeth. The consequence of this invasion is gingivitis, or inflammation of the gums, a condition that affects at least 70 to 90 percent of adolescents worldwide. In adults, continued poor oral hygiene may cause gingivitis to progress to periodontitis and the eventual loss of teeth. Some people are predisposed to this condition. And if that isn’t enough to give you tooth nightmares, consider that poor oral health is associated with cardiovascular disease.
Viral Gastroenteritis to Spite Us
Stomach flu, “winter vomiting,” “traveler’s diarrhea”—affectionate names for what is known clinically as viral gastroenteritis, an acute infectious illness of the tract by which food normally enters the human body, is broken down, and exits without event, more or less.
During an episode of gastroenteritis, unfortunately, there isn’t so much entering as exiting. Various highly contagious viruses are to blame, but rotavirus is one of the most frequent causes. In infants and children worldwide, it is the most common cause of severe diarrhea, according to the World Health Organization.
The U.S. Centers for Disease Control estimates that before the introduction of a rotavirus vaccine in 2006, every child in the country had been infected by age five. Viral gastroenteritis is transmitted primarily via the fecal-oral route, which includes eating sewage-contaminated shellfish.
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