[Behavior abnormality].

The aging rate of Japan is higher than 20% in 2005 and it is predominantly early and invites aged society in the developed countries. With increase in elderly person population, the emergency consultation of the elderly person increases, and the emergency medical treatment of the elderly person that complaining of a condition is vague must be careful to have possibilities to miss the severe condition of a patient. When an elderly person presents with sudden behavior abnormality and consults an emergency room, we must check presence of disturbance of consciousness. When there is disturbance of consciousness, we provide treatment for it. In this report, we describe an emergency disease with the behavior abnormality of the elderly person.