Hello i want to know about insomnia ?

Insomnia: Sleep disorder in which there is inability to fall asleep ;/or stay asleep, followed by daytime functional impairment. It accompanies several sleep, medical, or psychiatric disorders. It can occur at any age, but more common in elderly. It can be short-term (up to 3 weeks) or long-term. It can lead to memory impairment, mood changes, ; increase risk of heart disease ; accidents.