Primary insomnia is difficulty getting to sleep or staying asleep, or experiencing nonrefreshing sleep for at least 1 month. The term primary indicates that the insomnia is not caused by any known physical or mental condition.

There are numerous causes and risk factors. Primary insomnia is the most common sleep disorder. Everyday anxiety and stress, coffee, and alcohol are the most common culprits.

About 25% of elderly people and about 15% of the general population suffer from insomnia, but this includes all types of insomnia. Secondary insomnia may be caused by depression or other mental and physical illnesses.

Primary insomnia is often characterized by both difficulty falling asleep and by repeated awakenings. People often feel fatigued the next day. People who suffer from this are generally preoccupied with getting enough sleep. The more they try to sleep, the greater the sense of frustration and distress and the more elusive sleep becomes.

Clinical history (including all current medication and recreational drug use) and physical exam are usually sufficient to make the diagnosis. Polysomnography, an overnight sleep study, can be helpful to rule out other types of sleep disorders (such as breathing-related sleeping disorder).

Depression is a very common cause of secondary insomnia and it should be ruled out before primary insomnia is diagnosed. Often, insomnia is the symptom for which people with depression seek medical attention.

Depression includes more than 2 weeks of the following features: low mood or inability to feel pleasure in usually pleasurable things, a feeling of slowness or sluggishness of movement, or a feeling of agitation, irritability, anxiety, feelings of low self-worth or suicidal thoughts. Sleep can be too much, too little, unrefreshing or interrupted, especially with early morning wakening and inability to fall back asleep. Changes in appetite include eating too much or too little.

If you have insomnia, report any of these other symptoms to your health care provider so that you may be screened for depression. Antidepressant medications often solve insomnia problems related to depression, but some also cause sleep problems. If this occurs, medications may need to be adjusted.

Nonspecific measures to induce sleep (sleep hygiene):

• Using the bed only for sleep and sex
• Going to bed at the same time every night
• No daytime napping
• No caffeine, alcohol, or nicotine
• Eliminating the conditioned anxiety that comes with trying to sleep by reassuring yourself that you will sleep or distracting yourself
• Maintaining comfortable sleeping conditions
• Eating at regular times daily (avoiding large meals near bedtime)
• Exercising early in the day
• Getting out of bed if you are not asleep after 5-10 minutes and doing something else - going to another room may help reduce anxiety about falling asleep
• Practicing evening relaxation routines, such as progressive muscle relaxation or meditation

If the above recommendations are followed and the person continues to have insomnia, medications including benzodiazepines may be appropriate.

The prognosis is very good if the person sticks to the behavioral maneuvers (sleep hygiene). A doctor should evaluate chronic insomnia that does not improve.

It is important to remember that one's health is not at risk if one does not get 6 to 8 hours of sleep every day and that different people have different natural sleep requirements.

Some do fine on 4 hours a night, while others only thrive if they get 10-11 hours. Sleep requirements also change with age. Listen to your body's sleep signals and don't try to sleep more or less than is refreshing for you.

Daytime sleepiness is the most common complication, though there is some evidence that lack of sleep can also lower your immune system's ability to fight infections. Sleep deprivation is also a common cause of auto accidents -- if you are driving and feel sleepy, take a break.

Call your doctor if chronic insomnia has become a problem.