Insomnia affects people of all ages; however, senior citizens, women (especially after menopause) and those with a current depression or anxiety disorder are more likely to suffer from chronic insomnia.
There are several lifestyle-related factors that may produce insomnia. Persistent stress, such as a troubled marriage, a sickly child or a demanding job, can be a major cause of insomnia. Quality of sleep can also be impacted by environmental conditions, such as noise levels, extremes in temperature and changes in sleeping locations and time zones.
Some medications can also trigger episodes of sleeplessness. Nicotine and caffeine are stimulants that can prevent the onset of sleep or trigger awakenings throughout the night. Likewise, the ingredients in many popular over-the-counter medications for the flu, weight loss or asthma can lead to poor sleep.
The causes of chronic insomnia are more complex, often involving a variety of underlying mental or physical disorders, such as depression, arthritis, kidney disease, heart failure, asthma, sleep apnea, narcolepsy, restless legs syndrome, Parkinson's disease and hyperthyroidism.