Senile is a term referring to the condition of a person who has a group of symptoms involving progressive impairment of brain function. Senility may be diagnosed when two or more brain functions are impaired. These functions include language, memory, visual-spatial perception, emotional behavior or personality, and cognitive skills (such as calculation, abstract thinking, or judgment). Senility usually appears first as forgetfulness. Other symptoms may be apparent only with neurologic examination or cognitive testing.
Senility progresses slowly from decreased problem solving and language skills to difficulty with ordinary daily activities to severe memory loss and complete disorientation with withdrawal from social interaction.