By Linda Orlando Everyone in the world operates better throughout the day if they've had a good night's sleep. Even college students cramming at the last minute for an exam will do better on the test if they get at least six hours of sleep before they get up and sharpen their pencils. And with today's fast-paced world of jam-packed schedule and appointment-filled calendars, more and more people aren't getting the amount of sleep they need. But for some people, even getting eight or nine hours a night isn't enough to keep them from nodding off after lunch. If you're one of those people, you may be suffering from a serious sleep disorder that you don't even know you have-and if left untreated, it could eventually result in serious health consequences and even premature death. Obstructive sleep apnea, or OSA, is caused by a blockage of the airway during sleep, usually when the soft tissue in the rear of the throat collapses and closes. The word "apnea" is a Greek word that literally means "without breath." People who suffer from sleep apnea ("sleep without breath") literally stop breathing while they are sleeping. An apnea is clinically defined in adults as a cessation of breath that lasts at least ten seconds. Even children can suffer from sleep apnea, with an apnea being a cessation of breath that lasts the equivalent of two and a half missed breaths (the length of time is different depending on the age of the child). In addition to apneas, people with OSA can also have instances of hypopneas. The word "hypopnea" also comes from the Greek, with "hypo" meaning "less than normal," and "pnea" meaning "breath." A hypopnea is not an instance where the sleeper completely stops breathing, but instead the airflow is reduced or the sleeper is struggling to breathe. With each apnea and hypopnea, the oxygen level in the bloodstream typically drops, sometimes to dangerous levels. Sleep apnea is a very common disorder, but it is commonly overlooked or misdiagnosed. The National Institutes of Health estimate that at least 12 million American men, women, and children have undiagnosed or misdiagnosed sleep apnea. When a person with OSA is sleeping and has an apnea event, the brain briefly arouses the person in order to cause him or her to resume breathing. But this brief arousal results in extremely fragmented, poor quality sleep. People with untreated sleep apnea are not even aware of the awakenings, even though they may stop breathing, sometimes as high as hundreds of times during the night, and often for a minute or longer. They are aware, however, of being sleepy during the day. Loud snoring, sometimes interrupted by a period of silence, is a typical sign of sleep apnea, although it is not always present, especially in children. Risk factors for sleep apnea include a family history of sleep apnea, excess weight, a large neck, a recessed chin, smoking, excessive alcohol use, and abnormalities in the structure of the upper airway. Males, people over the age of 40, and certain ethnic groups (blacks, Pacific Islanders, and Mexicans) appear to be more at risk, but sleep apnea can affect both males and females of all ages, including children, irrespective of their weight. If you think you may have sleep apnea, a sleep study can determine whether or not you do, and if so, the severity of your symptoms. A sleep study is a very simple, non-invasive, non-medicated procedure where you spend the night in a hospital or clinic sleep lab. A technician attaches a few leads to your scalp and connects you to an EEG to monitor brain waves while you sleep, a little clip is fastened on your fingertip to monitor the oxygen saturation in your blood, and then all you do is go to sleep. It's practically as easy as spending the night in a hotel, but it provides much more than even a plush room in a 5-star hotel could offer you. This test could not only improve your quality of life, it could save your life. The American Sleep Apnea Association provides a short five-question test on their website to help you decide whether you may suffer from sleep apnea. Take the "What's Your Snore Score?" test, and if you answer "yes" to any of the questions, you should discuss your symptoms with your physician or a sleep specialist. You may also want to attend a meeting of an A.W.A.K.E. group in your area. A.W.A.K.E. stands for "alert, well, and keeping energetic"-characteristics that are definitely not the norm for people with untreated sleep apnea. Members of the A.W.A.K.E. Network are more knowledgeable about their disorder and treatments for it, and they are kept up-to-date on the latest developments and treatments. If sleep apnea is left untreated, the consequences to your health can be extremely serious, including even death. Untreated, sleep apnea can cause high blood pressure and other cardiovascular disease, memory problems, weight gain, and headaches. People with untreated sleep apnea may also complain of falling asleep inappropriately, morning headaches, feelings of depression, gastric reflux, nocturia (a need to use the bathroom frequently at night), premature aging, and impotence. Children with untreated sleep apnea may be hyperactive. Moreover, untreated sleep apnea, like sleep deprivation, may be responsible for not only declining health, but also job impairment and motor vehicle crashes. So if untreated sleep apnea causes you to fall asleep at the wheel, your failure to treat your medical condition could result in injury or death to others. Avoiding that tragic outcome is easy-all you have to do is spend a night in a sleep lab.