Insomnia is a serious sleep disorder. It can mean the inability to fall asleep or stay asleep throughout the night, or the tendency to wake too early before having gotten enough sleep. Insomnia is often used to describe the condition of waking up not feeling well-rested or restored, and is the most common reported sleep disorder among Americans. According to the National Sleep Foundation, between 30 and 40 percent of adults say they experience some symptoms of insomnia within a given year, and a recent study by the Centers for Disease Control and Prevention found the majority of Americans experience difficulty sleeping at least once a month.
Insomnia can range from mild to severe, acute (short-term sleeplessness) or chronic (insomnia that lasts for longer than a month), and can be a stand-alone disorder or a symptom of some other disease or condition, such as stress, drug use, or other health problems. People with insomnia often have day-time symptoms related to exhaustion, such as fatigue and decreased mental clarity.
There are two types of insomnia: primary and secondary.
Primary insomnia refers to sleep problems that are not directly associated with any other health condition. It isn’t a symptom or side-effect of another medical issue, but is its own disorder. This type of insomnia usually lasts for at least a month, and is thought to be caused by extreme life-changes, such as ongoing emotional stress and trauma.
Secondary insomnia is a symptom or side-effect of another emotional or physical problem, and is the most common type of insomnia. Health conditions such as depression or arthritis, certain medications, the use of alcohol and other drugs, or ongoing stress can all cause secondary insomnia. Stress-induced insomnia is the most common form of secondary insomnia, accounting for half of all those who’ve reported having symptoms of insomnia.
Written by: the Healthline Editorial Team
Published on Oct 15, 2010
Updated on Oct 11, 2012
Medically reviewed by Jennifer Monti, MD, MPH