Alzheimer’s disease has been broken down into several stages, however not everyone will experience every symptom. On average, people with Alzheimer’s live an average of eight years after diagnosis, but may survive anywhere between three to 20 years. Knowing which stage a loved one is at can help with decisions and treatment, as well as preparing for what is next. The stages are based on The Global Deterioration Scale, which outlines seven stages ranging from unimpaired function to severe cognitive decline.
Stage 1: Preclinical Stage
This is a newly added stage reflecting current evidence of biomarkers that can determine the disease years in advance. Currently there is no diagnostic criteria that doctors can use, but the guidelines propose further research to determine which biomarkers can be used. The symptoms of this stage include no cognitive impairment and no memory problems.
Stage 2: Early Stage
In this stage, there is very little cognitive decline. The person may experience difficulty in social situations and may experience memory lapses, but no signs of dementia can be detected by family members or during a medical exam.
Stage 3: Early Stage
Changes that occur during this stage are mild changes in memory and thinking, which can be detected on mental status tests but do not disrupt day-to-day life. During this stage, friends and family might start to notice a difference, with common difficulties including trouble remembering names, planning and organizing, difficulty preforming tasks, forgetting material they just read, and misplacing objects.
Stage 4: Early Stage
The person will experience moderate cognitive decline and should get a careful medical interview to detect clear-cut symptoms in areas including, forgetfulness, impaired ability in mental arithmetic, difficulty preforming complex tasks, and becoming moody or withdrawn.
Stage 5: Middle Stage
During this stage, there is moderate cognitive decline and the person will begin to need help with daily living, such as getting dressed or bathing. Symptoms of this stage include difficulty preforming tasks, confusion about time and place, inability to recall personal information like home address or phone number, but some may still be recalled such as details about one’s self or family.
Stage 6: Middle Stage
At this stage there is severe cognitive decline, with the memory continuing to worsen and personality changes may be taking place. Assistance will be needed to complete activities in daily life. Symptoms of this stage include wandering, changes in sleep patterns, difficulty remembering the name of a spouse or caregiver and difficulty remembering personal history.
Stage 7: Late Stage
Severe impairment has left the person unable to complete any activities in daily life, needing extensive assistance. In addition, communication is severely impaired, with the person not being able to respond to the environment, carry on a conversation, or control movement. Communication with words or phrase may be possible.
Resource: http://www.alz.org/national/documents/topicsheet_stages.pdf