Insomnia, also known as sleeplessness, is a __(31)__ disorder in which people have trouble sleeping. They may have difficulty falling asleep, or staying asleep __(32)__ desired. Insomnia is typically followed by daytime sleepiness, low energy, __(33)__, and a depressed mood. It may result in an increased risk of motor vehicle collisions, as well as problems __(34)__. Insomnia can be short term, lasting for days or weeks, or long term, lasting more than a month. The concept of the word insomnia has two possibilities: insomnia disorder and insomnia symptoms, and many __(35)__ of randomized controlled trials and systematic reviews often underreport on which of these two possibilities the word insomnia refers to.