Night terrors are a type of sleep disorder characterized by sudden and intense fear or anxiety, often accompanied by physical symptoms such as sweating, heart racing, and difficulty breathing. The person experiencing night terrors may thrash around in bed, scream, or cry out, but they typically do not remember the episode upon waking up. Night terrors are more common in children than adults, but can occur in both age groups. They are generally harmless and tend to resolve on their own as a person grows older.