There are four general areas important to good sleep hygiene:

• Our circadian rhythm, or 24-hour cycle
• Aging - sleep patterns change after age 40.
• Psychological stressors - those factors that increase arousals while sleeping.
• Common social or recreational drugs like nicotine, caffeine, and alcohol

Circadian Rhythm

Research has revealed that the body clock operates on a twenty-four hour schedule. This cycle is influenced by light and darkness. Circadian rhythm keeps the body alert during daylight hours and helps it to relax when night falls. This inner clock may even awaken you if you forgot to set your alarm. Unfortunately, it will also awaken you on days when you could sleep in.

The cycle may be altered by the timing of various factors, including naps, bedtime, exercise, and especially exposure to light (from travelling across time zones to watching TV in bed at night).

Aging

Aging also plays a role in sleep and sleep hygiene. After the age of 40 our sleep patterns change, and we have many more things to interrupt our sleep than in our younger years. These awakenings not only directly affect the quality of our sleep, but they also interact with any other condition that may cause arousals or awakenings, like the withdrawal syndrome that occurs after drinking alcohol close to bedtime. The more awakenings we have at night, the more likely we will awaken feeling unrefreshed and tired.

Psychological Stressors

Psychological stressors like deadlines, exams, marital conflict, and job crises may prevent us from falling asleep or wake us from sleep throughout the night. It takes time to turn off all the "noise" from the day. If you work right up to the time you turn out the lights, or are reviewing all the day's events and planning tomorrow, you simply cannot just "flip a switch" and drop off to a blissful night's sleep.