There are two kinds of night terrors: those in adults are frequently related to sleep apnea. In sleep apnea, the person actually stops breathing, and then (when reflex kicks in) awakens partially. Sometimes this triggers the night terror response. Night terrors in children can be caused by fevers, by medications, by stress in their life, and by sleep deprivation. Adults with night terrors should look into a sleep study--your doctor can refer you to a sleep specialist for this. For children, there aren't a lot of treatments available. Try to eliminate sugar and/or caffeine from their diet; start ramping activity down prior to bedtime--quiet story time or singing lullabies can help; try to eliminate stressors wherever possible.