Insomnia is a defined as a condition in which sleep is interrupted on a regular basis. You may have difficulty falling asleep or have early wakening. Early wakening can be either throughout the night or before your standard waking time, accompanied by difficulty returning to sleep. You may also feel tired or irritable and may have trouble concentrating during the day. Primary insomnia is sleep disruption unassociated with other symptoms. Secondary insomnia involves sleep disruption associated with another condition such as chronic pain or medication side effects. In acute insomnia, you may have a period of a few nights or more when sleep is not easy, but it is short lived. Chronic insomnia is diagnosed when sleep is interrupted three or more nights a week for a month or more. Insomnia can be caused by many factors, including stress, depression, anxiety and worry. The diagnostic process may include a sleep study, which usually involves an overnight stay in a sleep lab, where a record of your stages of sleep is developed to determine any patterns which may be contributing to your interrupted sleep. A full evaluation of your sleep hygiene will help you understand what factors are involved in your individual case. Treatment may include medication, cognitive behavior therapy and sleep hygiene improvement.