It is inconvenient and can ware you down fast. Intermittent insomnia is most likely to occur in people who are female, tend to be depressed and over the age of 60. It also occurs as a side effect of medication, stress, environmental stress and travel.
Chronic insomnia can be a sign of more serious physical and mental conditions.
It can also be caused by behavior such as shift work and overuse of drugs, alcohol and caffeine. When you don't get a refreshing night's sleep, it not only makes you less functional the next day but may slow your recovery from an illness and can lead to emotional or mental problems. It varies from rest-less or disturbed sleep to a reduction in the usual time spent sleeping and, in the extreme, may involve complete wakefulness.