Confusion is a change in mental status in which a person is not able to think with his or her usual level of clarity. Frequently, confusion leads to the loss of ability to recognize people and or places, or tell time and the date. Feelings of disorientation are common in confusion, and decision-making ability is impaired. Confusion may arise suddenly or develop gradually over time. Confusion has multiple causes, including injuries, medical conditions, medications, environmental factors, and substance abuse.