Ghost sickness is a culturally-related grief condition which is characterized by weakness, frequent nightmares, difficulties in breathing, loss of appetite, and feelings of terror. The symptoms are believed to be due to ghosts (specially when someone has just passed away) or witchcraft. Ghost sickness has been observed among some indigenous groups such as the Navajo, Muscogee, and Polynesian peoples. Contemporary theories associate this condition with psychological trauma as manifested through chronic sadness, withdrawal, hyper-vigilance, and guilt. Regarding a psychosocial perspective, ghost sickness may be attributed to identification with ancestral agony and death.