National Sleep Awareness Week
Dr. Ilene Rosen and Dr. Richard Schwab, with Penn’s Division of Sleep Medicine, spend their days examining and explaining to patients what may be causing their lack of sleep. Since this is National Sleep Awareness Week, these sleep physicians are offering up some little known facts.
Fact #1: Getting up during the night to urinate may be a sign of sleep apnea.
Explanation: When you stop breathing because of closure of the passageway between the back of the throat and the windpipe, the brain works very hard to keep your oxygen levels up. It sends signals to your respiratory muscles, especially your diaphragm, to work harder. This increased work of the muscles of the chest cause pressure changes in the chest, which are felt by the heart muscle. The stress on the heart muscle causes the muscle cells to secrete a substance, which fools the kidneys into making urine! (Rosen)
Fact #2: Decreased interest in sex or impotence can be a sign of sleep apnea.
Explanation: Patients with sleep apnea often complain of decreased libido and lose their interest in sex. Some of this is related to sleep deprivation that results from sleep apnea. Sleep apnea can also cause impotence. Treatment of sleep apnea can improve libido and may help impotence. (Schwab)
Fact #3: Alcohol is a terrible sleep aide.
Explanation: Although alcohol will cause sleepiness and may help a patient to initially fall asleep, it actually causes significant sleep disruption later in the night. Any type of alcohol (beer, wine, liquor) will disturb sleep. Alcohol will also worsen snoring and sleep apnea. Alcohol should never be used as a sleeping aide. (Schwab)
Fact #4: Waking up and feeling awake, but being unable to move, may be a sign of a serious sleep disorder.
Explanation: Sleep paralysis is sometimes also referred to as the “witch is riding your back.” It occurs when the brain awakens from Rapid Eye Movement (REM) sleep. During normal REM sleep, the brain is very active (it is the time of the night when dreaming often occurs.) During this stage of sleep, the brain sends a signal to the skeletal muscles in the body and paralyzes, or immobilizes, them. The only muscles that work are the diaphragm, the main muscle that helps us breathe and the eye muscles (hence, the name “rapid eye movement” sleep). If the brain awakens before the signal that immobilizes the muscles is turned off, the person will wake-up but still be paralyzed. This can be a very scary experience that lasts for a few seconds and then breaks. Although normal people can have sleep paralysis, this can also be a symptom of sleep deprivation, sleep fragmentation and narcolepsy. (Rosen)
Fact #5: If you need two or more medicines to control your blood pressure, you may have obstructive sleep apnea. This is even more likely if you are overweight.
Explanation: Studies have shown that patients with difficult-to-control hypertension (defined as requiring two or more medications) have a higher prevalence of obstructive sleep apnea. While we don’t know the cause, patients with refractory hypertension who also have sleep apnea are noted to have decreases in blood pressure and better-controlled blood pressure once they are placed on CPAP (continuous positive airway pressure masks worn to improve and prolong sleep). (Rosen)
Fact #6: Exercise or eating within three hours of going to bed could be the reason you are having trouble falling asleep.
Explanation: While exercise will help you relax, in general, and usually helps consolidate sleep, exercising too close to bedtime will delay the time your body unwinds and is able to fall asleep. The chemicals that increase in your body immediately after exercising and eating are associated with increased wakefulness and will delay the time your body feels ready to sleep. (Rosen)
Fact #7: Heartburn during sleep may be a sign of sleep apnea.
Explanation: Patients with sleep apnea often complain of heartburn during sleep and treatment of sleep apnea will improve the heartburn. (Schwab)
Fact #8: If you work the night shift and are having trouble going to bed during the day, try wearing dark sunglasses—in all types of weather—on the commute home.
Explanation: Our ability to stay awake and fall asleep is a function of two processes. First, there is a homeostatic switch that drives sleep that is located in the brain. As soon as we wake up, chemicals build up in our brain. The build-up of these chemicals is associated with the need to go back to sleep at the end of the day. Counteracting this drive for sleep is the biological clock. The clock function with a rhythm that drives our wakefulness, known as the circadian rhythm. Early in the morning, after being up all night, the sleep hemostat is primed for sleep. However, although the circadian clock has just hit its lowest point in its curve, the exposure to daylight on the commute home “reminds” the clock that the day is beginning and the circadian drive for wakefulness increases. Thus, wearing dark sunglasses will “fool” the clock into thinking it is still dark and delay the clock enough to allow for sleep to occur after the night shift is over. (Rosen)
Fact #9: Falling asleep at movies or watching TV can be a sign of sleep apnea.
Explanation: Patients with sleep apnea have frequent arousals at night secondary to recurrent apneas (no airflow). These arousals cause significant sleep fragmentation, which results in daytime sleepiness. Commonly, patients with sleep apnea will fall asleep after dinner, watching TV or at a movie in a theater. Such patients can also fall asleep at red lights while driving. (Schwab)
Almanac, Vol. 52, No. 27, March 28, 2006