What does sleep disorders actually mean--insomnia?

Insomnia. Insomnia means inability to fall asleep inability to maintain sleep early morning awakening non restorative sleep this is given you have adequate time and opportunity to get good sleep.
Can't sleep. We should be able to sleep soundly for 7-8 hours without many interruptions. Inability to do that is called a "sleep disorder." there are two main types: disorders of sleepiness, where you are too sleepy, and disorders of insomnia, where you can't either fall asleep or stay asleep. There are a number of causes, and i would recommend seeing a sleep specialist if this affects you.