Insomnia is a common sleep disorder. People who have insomnia have trouble falling asleep, staying asleep, or both. As a result, they may get too little sleep or have poor-quality sleep. They may not feel refreshed when they wake up.
Insomnia can be acute (short-term) or chronic (ongoing). Acute insomnia is common and often is brought on by situations such as stress at work, family pressures, or a traumatic event. Acute insomnia lasts for days or weeks.
Chronic insomnia lasts for a month or longer. Most cases of chronic insomnia are secondary, which means they are the symptom or side effect of some other problem. Certain medical conditions, medicines, sleep disorders, and substances can cause secondary insomnia.
In contrast, primary insomnia isn't due to medical problems, medicines, or other substances. It is its own distinct disorder, and its cause isn’t well understood. Many life changes can trigger primary insomnia, including long-lasting stress and emotional upset.
Insomnia can cause daytime sleepiness and a lack of energy. It also can make you feel anxious, depressed, or irritable. You may have trouble focusing on tasks, paying attention, learning, and remembering. These problems can prevent you from doing your best at work or school.
Insomnia also can cause other serious problems. For example, you may feel drowsy while driving, which could lead to an accident.