The most common sleep disorder is insomnia. Others are sleep apnea, narcolepsy and hypersomnia (excessive sleepiness at inappropriate times), sleeping sickness (disruption of sleep cycle due to infection), sleepwalking, and night terrors.Encyclopedia Entry for Sleep Disorders :Sleep disorders - overview. There are more than 100 different sleeping and waking disorders. They can be grouped into 4 main categories: Problems falling and staying asleep (insomnia) Problems staying awake (excessive daytime sleepiness) Problems sticking to a regular sleep schedule (sleep rhythm problem) Unusual behaviors during sleep (sleep-disruptive behaviors) PROBLEMS FALLING AND STAYING ASLEEP Insomnia includes trouble falling asleep or staying asleep. Episodes may come and go, last up to 3 weeks (be short-term), or be long-lasting (chronic). PROBLEMS STAYING AWAKE Hypersomnia is a condition in which people have excessive daytime sleepiness, meaning that they feel tired during the day. Hypersomnia can also include situations in which a person needs to sleep a lot. This may be due to other medical conditions, but can also be due to a problem in the brain. Causes of this problem include: Medical conditions, such as fibromyalgia and low thyroid function Mononucleosis or other viral illnesses Narcolepsy and other sleep disorders Obesity, especially if it causes obstructive sleep apnea When no cause for the sleepiness can be found, it is called idiopathic hypersomnia. PROBLEMS STICKING TO A REGULAR SLEEP SCHEDULE Problems may also occur when you do not stick to a regular sleep and wake schedule. This occurs when people travel between time zones and with shift workers who are on changing schedules, especially nighttime workers. Disorders that involve a disrupted sleep schedule include: Irregular sleep-wake syndrome Jet lag syndrome Shift work sleep disorder Delayed sleep phase, as in teenagers who go to sleep very late at night and then sleep until noon Advanced sleep phase, as in older adults who go to sleep early in the evening and wake up very early Irregular sleep SLEEP-DISRUPTIVE BEHAVIORS Abnormal behaviors during sleep are called parasomnias. They are fairly common in children and include: Sleep terrors Sleepwalking REM sleep-behavior disorder (a person moves during REM sleep and may act out dreams).Insomnia; Narcolepsy; Hypersomina; Daytime sleepiness; Sleep rhythm; Sleep disruptive behaviors; Jet lag.Irregular sleep Irregular sleep Sleep patterns in the young and aged Sleep patterns in the young and aged.Kryger MH, Rosenberg R, Martin L, Kirsch D. Hypersomnolence.Encyclopedia Entry for Sleep Disorders :Sleep disorders in older adults. Sleep problems are common in older adults. The amount of sleep needed stays constant throughout the adult years. Doctors recommend that adults get 7 to 8 hours of sleep each night. In older adults, sleep is less deep and choppier than sleep in younger people. Sleep patterns in the young and aged A healthy 70-year-old may wake up several times during the night without it being due to disease. Sleep disturbances in older adults may be due to any of the following: Alzheimer disease Alcohol Changes in the body's natural internal clock, causing some people to fall asleep earlier in the evening Long-term (chronic) disease, such as heart failure Certain medicines, herbs, supplements, and recreational drugs Depression (depression is a common cause of sleep problems in people of all ages) Brain and nervous system conditions Not being very active Pain caused by diseases such as arthritis Stimulants such as caffeine and nicotine Frequent urination at night.Symptoms that may occur include: Difficulty falling asleep Difficulty telling the difference between night and day Early morning awakening Waking up often during the night.The health care provider will take a history and perform a physical exam to look for medical causes and determine which type of sleep disorder is causing the problem.Relieving chronic pain and controlling medical conditions such as frequent urination may improve sleep in some people. Treating depression can also improve sleep. Sleeping in a quiet room that isn't too hot or too cold and having a relaxing bedtime routine may help improve symptoms. Other ways to promote sleep include these healthy lifestyle tips: Avoid large meals shortly before bedtime. Avoid stimulants such as caffeine after mid-afternoon. Get regular exercise early in the day. Go to bed and wake up at the same time every day. DO NOT take naps. Use the bed only for sleep or sexual activity. If you can't fall asleep after 20 minutes, get out of bed and do a quiet activity such as reading or listening to music. Avoid using sleeping pills to help you sleep, if possible. They can lead to dependence and can make sleep problems worse over time if you don't use them the right way. Your provider should assess your risks of daytime sleepiness, mental (cognitive) side effects, and falls before you begin taking sleep medicines. If you think you need sleeping pills, talk with your provider about which pills are safe for you when taken properly. Certain sleeping pills should not be taken on a long-term basis. DO NOT drink alcohol at any time when you are using sleeping pills. Alcohol can make the side effects of all sleeping pills worse. WARNING: The FDA has asked manufacturers of certain sleep medicines to put stronger warning labels on their products so that consumers are more aware of the potential risks. Possible risks while taking such medicines include severe allergic reactions and dangerous sleep-related behaviors, including sleep-driving. Ask your provider about these risks.For most people, sleep improves with treatment. However, others may continue to have sleep disruptions.Possible complications are: Alcohol use Drug abuse.Call for an appointment with your provider if a lack of sleep or too much sleep is interfering with daily living.Getting regular exercise and avoiding as many causes of sleep disruption as possible and adequate exposure to natural light may help control sleep problems.Insomnia - older adults.Sleep patterns in the young and aged Sleep patterns in the young and aged.Shochat T, Ancoli-Israel S. Insomnia in older adults.