Normally, the sleeping and waking cycles of human beings are set by an internal clock that takes its cues from the cycle of daylight and darkness as the sun rises and sets. With the advent of artificial lights throughout human history, first with firelight, then oil lamps, and finally electricity-driven lights, people have become disconnected from their zeitgebers, or environmental signals to the body. A study on Americans found that the average person received only 21 minutes of sunlight every day. For others who travel frequently across time zones, suffer jet lag, or those whose work schedule changes constantly, their circadian rhythms are even more out of sync. Delayed and advanced circadian rhythm sufferers face the inability to get up in the morning and early morning insomnia, respectively.
Fifty percent of all adults have had issues with insomnia during their lives, keeping them from falling asleep or staying asleep as long as they wanted. Some experts believe that ten percent of adults suffer from chronic insomnia that affects most of their sleep. Most believe that insomnia is a result and not a disease in itself to be treated. Writing down worries before bed can help those who suffer from a wakeful mind before sleep, and following the 10 Commandments of Healthy Sleep can help insomnia sufferers as well.
On the other hand, narcolepsy is a neurological disease that may be genetic. It results in excessive daytime sleepiness that can be so overwhelming that the patient cannot help but fall asleep. Their sleep may last for less than a minute to over an hour, which is rare. Most adults begin to suffer from narcolepsy in their 20s and 30s, although it can manifest in children. In some rare instances, adults in their 50s can suffer from the disease.
Narcolepsy can progress to the point where a severe muscle weakness known as cataplexy occurs. It can also progress into alarming hallucinations while the patient is awake and asleep, and into sleep paralysis. Sleep paralysis is a condition where a patient is fully aware, but unable to move when falling asleep or waking up. Narcolepsy can be managed with a drug regimen, but is itself incurable. As some patients age towards 60, the effects of narcolepsy seem to weaken.
Restless leg syndrome (Willis-Ekbom Disease) is an overwhelming urge to move legs that can be found alongside sleep apnea sufferers. Restless leg syndrome’s effects are suffered most at nighttime upon going to bed, and though movement can immediately relieve it, it interferes with sleep as well.
Parasomnias include a large selection of undesirable emotional and physical reactions that happen at the nexus of sleep and awake. Sleep terrors, also known as night terrors, are difficult especially in children as they make the sufferer thrash about wildly. Those suffering from night terrors are often inconsolable and cannot remember the event during the daytime.