Insomnia
Sleeplessness, Sleep Disorder

Stress is the primary cause of insomnia, but there are also physical conditions that can bring on the condition. Your doctor should rule these out first. They include sleep apnea, overactive thyroid, certain medications, and gastrointestinal problems such as gastroesophageal reflux.

Lack of sufficient physical activity during the day can interfere with the body's drive for sleep. Substance abuse can also be a major sleep disruptor.

Insomnia most often occurs in response to how people handle a bad night or a few bad nights of sleep. People often try to compensate for a brief sleepless period by sleeping later, napping in the afternoon, having a few drinks before bed, or going to bed early. But those actions only lessen the body's natural sleep drive or cause more early wakefulness. Because the anxious brain quickly learns to associate the bedroom with wakefulness, a self-defeating cycle takes on a life of its own.

Some people are at risk of insomnia by virtue of such environmental factors as shift work and jet lag. People who do not get enough exposure to sunlight during the day can also have trouble sleeping. And such factors as drinking too much caffeine or overheating a bedroom can also interfere with sleep.