Sleep insomnia overall is a sleep disorder that can make it hard to sleep, hard to stay asleep, and wake up too early and not being able to fall back to sleep. Sleep insomnia is relatively common among people and there are different types of insomnia: Transient, Acute, and Chronic and their causes. Transient insomnia is a very short period (about a week) of trouble sleeping through the night or waking up in the middle of the night. Acute insomnia is also a short period (one week to a few weeks) of trouble falling asleep, poor attention during the day, and fatigue/daytime sleepiness. Chronic insomnia is a longer period (about a month) of trouble sleeping, irritability, or mood changes such as depression. The overall causes of sleep insomnia are stress, irregular sleep schedule, poor sleeping habits, and mental health disorders like anxiety and depression.