Sleep: What's Going On Behind That Shut-Eye
Have you ever watched someone sleep and wondered what he or she was dreaming? The person’s outward appearance would never give it away: slow breathing, eyes occasionally fluttering, but mostly the very picture of peace and stillness. But, appearances can be deceiving. When people sleep, there’s a lot more going on than meets the eye. The notion of sleep as the body’s ultimate “down time” has some truth to it, but sleep is also an active process, in which the brain can be remarkably active, even if the body remains (mostly) immobile.
Why Do We Sleep?
The function of sleep is not entirely clear, but researchers believe that REM(Rapid-eye movement) sleep is important for solidifying memories, and perhaps for even more critical functions. Rodents completely deprived of REM sleep die after a few weeks. Non-REM sleep, meanwhile, seems to be important in providing a sense of restored energy and ability to concentrate during the day. A number of theories about sleep attempt to explain its role or roles: a restorative for the mind and body in preparation for the day ahead; or a way of reducing energy consumption, to save energy for activities occurring during the day. Some scientists believe that sleep is evolution’s way of improving survival by preventing animals from preying on each other 24 hours a day.
There are more than 80 individual sleep disorders, but they are divided into 4 main categories:
• Dyssomnias, in which there is insomnia (difficulty initiating or maintaining sleep), sleepiness during the day, and abnormal sleep-wake timing; examples include sleep apnea and the effects of medications or alcohol
• Parasomnias, in which there is abnormal behavior around sleep, but without excessive sleepiness or insomnia; examples include sleepwalking or night terrors
• Medical-psychiatric sleep disorders, in which a condition that causes other problems disrupts or impairs sleep; examples include anxiety, depression, Parkinson’s disease, dementia or gastroesophageal reflux disease (GERD)
• Sleep problems that cannot be clearly separated from normal variation, or for which there is no consensus among experts; examples include pregnancy-associated sleep disorder and sleep hyperhidrosis (excessive and unexplained sweating during sleep)
Good Advice for Getting a Good Night’s Sleep
There are changes you can make to improve your chances of getting a good night’s sleep. Sleep experts call this “sleep hygiene,” and these measures are routinely recommended for almost anyone complaining of sleep trouble. Some are just common sense, but, unfortunately, many people for whom sleep is a problem do not recognize their importance. Here are some general guidelines to follow:
• Establish a schedule and stick to it; sleep when you are sleepy but try to get up and go to bed each day at about the same time.
• Use a fan or other means of creating a steady, soothing sound to drown out other noises.
• Reduce alcohol and caffeine intake; avoid caffeine after noon and don’t use alcohol as a sedative before bed.
• Get heavy curtains or shades to block out bright light early in the morning if you are awakening earlier than you’d like.
• Check your medication list. Because some medicines can interfere with sleep, ask your doctor or pharmacist about the medicines you take.
• Do not exercise vigorously after within several hours of bedtime.
• Avoid heavy meals or excessive fluids within an hour or two of bedtime.