Alzheimer's is a disease that impairs the brain's normal functioning. Deficits are represented by various symptoms and behavior changes. The
following problems represent the general characteristics usually seen in Alzheimer's disease. However, a person may or may not exhibit all of these problems. 
General Problems of Dementia
• Memory loss, confusion
• General loss of intellectual abilities
• Unable to follow instructions, perform routine tasks
• Catastrophic reactions (overreacting to overwhelming situations)
• Loss of personality
• Loss of sense of time
• Aphasia - speech and communication difficulties (understanding and being understood)
• Agnosia - inability to recognize common people or objects
• Apraxia - loss of ability to perform purposeful motor movements
General Problems of Behavior
• Denial of problems
• Wandering, sleep disturbances
• Sundowner's Syndrome (behavior worsens in the evening)
• Inappropriate sexual behavior/comments
• Losing/hiding things
• Repeats actions/questions
• Clinging behavior (following you around everywhere)
• Complaints, insults, demanding things
General Problems of Mood
• Depression, suicidal thoughts or feelings
• Apathy or listlessness
• Anger, agitation, anxiety, restlessness
• False ideas and beliefs (delusions)
• Suspiciousness and accusing others
• Paranoia
• Hallucinations (a person may see, hear, feel or smell things that are not there)
• Misinterpretation of actions, events, conversations