Insomnia: Difficulty falling asleep or staying asleep, fatigue after waking up, loss of energy, appearing at least three times a week for more than one month. Which of the following situations best describes insomnia? ['Xiao Wang has been sleepwalked several times in the past two months.', 'Lao Zhang only slept for three hours a day in recent years.', 'Miss Zhang woke up almost every night for five weeks and lost her energy during the day.', 'Mr. Liu cannot sleep all night on business trips.']