Now consider noise. If a ticking clock disturbs you, buy one that doesn't tick, or use your phone. Turn clock radios and MP3 players to the wall and cover lighted screens. Lay in supplies of earplugs, eye masks, and anything else that helps screen out light as well as sound. Some people find a fan or white-noise machine is soothing and blocks out street noise. If you don't like wearing earplugs or an eye mask when you fall asleep, keep them on your bedside table in case you wake up later. Many people find they're more sensitive to light and sound in the middle of the night.
^ Tranah, Gregory J.; Blackwell, Terri; Stone, Katie L.; Ancoli‐Israel, Sonia; Paudel, Misti L.; Ensrud, Kristine E.; Cauley, Jane A.; Redline, Susan; Hillier, Teresa A. (2011). "Circadian activity rhythms and risk of incident dementia and mild cognitive impairment in older women". Annals of Neurology. 70 (5): 722–732. doi:10.1002/ana.22468. ISSN 1531-8249.
Interestingly, it has been shown that the sleep-wake cycle acts on the beta-amyloid burden which is a central component found in AD.[29][30] Indeed, during waking, the production of beta-amyloid protein will be more consistent than during sleep.[29][30][32] This is explained by two phenomena. The first is that the metabolic activity will be higher during waking and thus will secrete more beta-amyloid protein.[29][30] The second is that oxidative stress will also be higher and lead to increased AB production.[29][30]
Another systematic review noted 7-16% of young adults suffer from delayed sleep phase disorder. This disorder reaches peak prevalence when people are in their 20s.[57] Between 20 and 26% of adolescents report a sleep onset latency of >30 minutes. Also, 7-36% have difficulty initiating sleep.[59] Asian teens tend to have a higher prevalence of all of these adverse sleep outcomes than their North American and European counterparts.[59]

In Alzheimer's disease, in addition to cognitive decline and memory impairment, there is also significant sleep disturbances with a modified sleep architecture.[30][29] The latter may consist in sleep fragmentation, a reduction in sleep duration, insomnia, an increase daytime naping, a decreased quantity og some sleep stages and a resemblance between some sleep stages (N1 and N2).[29] More than 65% of people with Alzheimer's disease suffer from this type of sleep disturbance.[29]
Frequently having trouble sleeping can be a frustrating and debilitating experience. You sleep badly at night, which leaves you feeling dead-tired in the morning and whatever energy you have quickly drains throughout the day. But then, no matter how exhausted you feel at night, you still have trouble sleeping. And so the cycle begins again, taking a serious toll on your mood, energy, efficiency, and ability to handle stress. Ignoring sleep problems and disorders can damage your physical health and lead to weight gain, car accidents, impaired job performance, memory problems, and strained relationships. If you want to feel your best, stay healthy, and perform up to your potential, quality sleep is a necessity, not a luxury.
What to do: If you suspect you have a circadian rhythm disorder, take steps to get your body onto a regular sleep schedule. Choose a bedtime and wake-up time that work for you, and follow the same routine each day, even on weekends. This can be tough for those who have to get up early during the week but like to stay up later on weekends, but do your best to craft a compromise between your work week and weekend habits. The important thing is to avoid the trap of sleeping from 10 p.m. to 6 a.m. during the week, then suddenly shifting to late nights and late mornings on the weekends. This will inevitably leave you with insomnia on Sunday night, which in turn sets you up to start the week exhausted on Monday morning.