Night terrors, also known as sleep terrors, are episodes of screaming, intense fear, and flailing while still asleep. They are considered a parasomnia, an undesired occurrence during sleep, and are classified as a disorder of arousal, meaning they occur during N3 sleep, the deepest stage of non-rapid eye movement (NREM) sleep. Night terrors are most common in children, but adults can also suffer from them. The following are some of the causes of night terrors in adults:

• Stress or trauma
• Sleep deprivation
• Sleeping with too much light or noise, or in an unfamiliar environment
• Obstructive sleep apnea
• Restless legs syndrome
• Migraines

It is important to note that brain lesions are an unlikely cause of night terrors. If night terrors are causing problems getting enough sleep or pose a safety risk, they may require treatment.