Confusion may range from mild to severe. A person who is confused may:

• Be unable to express his or her thoughts clearly.
• Behave in an unusual, bizarre, or aggressive manner.
• Have trouble solving problems and performing simple tasks.
• Not know where he or she is. Be unable to recognize family members or familiar items.
• Express firmly held but false beliefs (delusions).
• See, hear, feel, smell, or taste things that are not really there (hallucinations or illusions).
• Believe that others want to harm him or her (paranoia).