The way the disease proceeds and the array of symptoms that arise over time can vary from person to person. For consistency, physicians use the following staging system to identify the progression of the disease:
 
Stage 1: No impairment
The person has no memory problems, no perceptible symptoms, and is functioning normally.
 
Stage 2: Very mild cognitive decline
Decline in memory or thought processing may be normal for the person’s age or may be the first signs of Alzheimer’s. The person may complain of memory lapses, such as forgetting familiar words or losing personal items, like glasses and keys. But these are subjective indicators, and problems probably will not be apparent yet to friends or family members.
 
Stage 3: Mild cognitive decline
The person may:
  • Not remember the names of new people they are introduced to
  • Have a noticeably impaired ability to work or interact socially
  • Lose or misplace valuable items
  • Have a marked inability to plan or organize
Stage 4: Moderate cognitive decline
The person may:
  • Not recall recent events
  • Be unable to perform relatively challenging mental tasks, such as counting backwards from 100 by 7s
  • Have a diminished ability to do complicated everyday tasks, such as shopping and paying bills
  • Not remember significant events in his or her own life
  • Begin to be withdrawn, particularly in challenging situations
Stage 5: Moderately severe cognitive decline
The person may:
  • Not remember important information, such as their address or telephone number
  • Know where they are, the day of the week, the month, or the season
  • Have trouble with less challenging mental tasks, such as counting backwards from 40 by 4s
  • Need help choosing clothing appropriate for the season or the setting
  • Retain knowledge about themselves, such as their own name and the names of their immediate family members
  • Eat, use the toilet, and perform similar personal functions on their own.
Stage 6: Severe cognitive decline
The person may:
  • Be unaware of their surroundings and recent events
  • Know their own name, but not remember their own personal history very well
  • Sometimes forget their spouse’s name, but distinguish familiar from unfamiliar people
  • Need assistance to dress
  • Have an abnormal sleep/waking cycle
  • Need help using the toilet (wiping, disposing of toilet paper, or flushing toilet)
  • Develop urinary or fecal incontinence
  • Undergo personality changes, such as extreme suspiciousness
  • Experience delusions or hallucinations, or exhibit compulsive, repetitive behaviors such as hand-wringing
  • Wander and become easily lost
Stage 7: Very severe cognitive decline
The patient may:
  • Lose their ability to speak coherently (although they may utter occasional words or phrases)
  • Need help with eating, using the toilet, and personal hygiene
  • Have general urinary incontinence
  • Be unable to walk or sit without help
  • Eventually, be unable to hold up their head or swallow