You are suffering from insomnia if you usually have trouble falling or staying asleep. There's no cure, but people with insomnia are told to go to be at the same time every night, and try to clear their mind of stress.
And if you are a person who has a lot of sleepless nights, you could be labeled an insomniac. The noun insomnia was borrowed from Latin insomnis "sleepless," from the prefix in- "not" plus somnus "sleep." Latin somnus is actually related to Greek hypnos "sleep," the source of English words such as hypnosis.
