Insomnia is the inability to fall asleep or maintain sleep throughout the night. When it first develops it is called Acute Insomnia. With insomnia, you usually awaken feeling unrefreshed, which takes a toll on your ability to function during the day. Acute Insomnia can develop after a severe disturbing event or from a conditioned response from poor Sleep Hygiene. When these sleep issues last for longer periods it is called Chronic Insomnia.