Insomnia, which literally means “sleeplessness,” is the difficulty of falling asleep or staying asleep. Insomnia may be temporary or it may be recurring (chronic). If you suffer from insomnia, you are not alone. By some estimates, 1 out of every 4 Americans deals with temporary insomnia, and 1 in 10 suffers from chronic insomnia.

Even during sleep, the brain is still active, moving through the stages of what is known as the sleep cycle. The sleep cycle has five recognized stages, and a full cycle lasts about 90 minutes. Therefore, during the course of a typical night, a person undergoes several sleep cycles.

The stages of the sleep cycle are: 

• Stages 1 and 2: Light sleep, during which eye movements are slower, breathing and heart rate decreases. 
• Stages 3 and 4: These are the deep sleep stages, also called the “delta” stages. Stages 3 and 4 are the most restful and refreshing part of the sleep cycle. As a person gets older, they may spend less time in these sleep stages. 
• Rapid Eye Movement (REM) Sleep: This is the final stage of the sleep cycle. During REM sleep, the eyes move rapidly and the person may experience vivid dreams. Breathing is also rapid, and the heart rate increases.

Although a typical night’s sleep is about 8 hours, the amount of sleep a person needs varies from person to person. Some people can function well on fewer hours of sleep, while others may need as much as 10 hours per night.

The body’s natural clock, called the circadian rhythm, varies by age and may be due to natural changes in levels of melatonin, which is a brain hormone. Teens may require more sleep but may only feel sleepy at a later hour, which is called “delayed sleep phase syndrome.” While adults may think that a teenager is just being difficult, the delayed sleep phase syndrome may be the result of changing melatonin-based hormonal changes. By contrast, elderly people may feel sleepy earlier in the evening and even may need less sleep, or require naps during the day.

If you have difficulty sleeping, the key to treating insomnia is figuring out the underlying cause. 

The causes of insomnia include:

• Stress or anxiety
• Sleep apnea, or unconscious pauses in breathing
• Restless leg syndrome/periodic limb movement disorder
• Depression
• Certain medications, such as pseudoephedrine
• Excessive stimulants, such as alcohol, nicotine or caffeine
• Pain or discomfort, such as arthritis or heartburn
• Anxiousness about not being able to fall asleep, called “psychophysiologic insomnia”
• Circadian rhythm disorders (disorders of the body’s natural clock)
  

A lack of sleep can make you tired, irritable or affect daily activities. For example, the National Highway Transportation Safety Administration reported that drowsy driving causes more than 100,000 crashes a year, resulting in 40,000 injuries and 1,550 deaths.

Lack of sleep can also weaken the immune system, making the person more prone to chronic infections, such as colds.

Here are some things you can do to improve your sleep habits:

• Limit your use of stimulants, such as alcohol, caffeine or nicotine at bedtime.
• Exercise daily, but avoid exercising just prior to bedtime.
• Avoid eating large meals just before bedtime, as this may lead to heartburn or other discomforts.
• Try to set up a routine: going to bed the same time every day, and waking up the same time every day, including on weekends. This will help set your circadian rhythm.
• If you are worried or anxious about events in your life, write them down before you go to bed rather than worrying about them through the night.
• Avoid naps during the day.
• Use your bedroom for restful activities. Avoid using the bedroom for stress-inducing activities, such as work, eating, watching TV, or even playing video games.
• Create a restful environment for environment, such as darkening the room by using heavy curtains or reducing distracting noises by using a fan.