It is distinguished between different degrees of Alzheimer’s disease. With the so-called Reisberg scale the course of the disease can be defined in 7 successive stages.
The stages 1 and 2 are classified as health. The Stage 2 describes the feeling of the family that the person concerned is suffering from increasing forgetfulness. But the memory problems are not striking. Increasing forgetfulness may have other reasons. The abnormalities described in this stage are still considered „normal.“
3 and 4 are stages in which most frequently the diagnosis of Alzheimer’s disease is provided.
In stage 3, low cognitive declines can be observed. Complex tasks can not be solved, the orientation is more difficult, amnesic aphasia and forgetfulness are beginning to attract attention. One speaks of mild dementia.
In stage 4 moderate cognitive decline becomes significant; the person concerned has increasing problems with calculating and with coping with the financial management, the mobility is limited. The person concerned needs help with difficult tasks of daily life, the deficiencies are often denied and situations that make demands are avoided. There is a mild to moderate dementia.
Stage 5 is referred to as moderate dementia. Frequently there is temporal and spatial disorientation (date, day, time of year etc.). Although no help in toileting or eating is needed, there may be difficulties in selecting suitable clothing or with the correct sequence when getting dressed. Many activities of daily living can no longer be carried out without aid. Everyday knowledge such as address or telephone number will be forgotten. Dementia can no longer be denied.
In stage 6 severe cognitive decline becomes significant and it often professional care is needed. The person concerned needs support in everyday activities – he/she can become for example, incontinent, or needs help to find his/her way at known locations. Changes in personality, behavior and emotion (anxiety, agitation, beating) are becoming clearer. Seasons and seasonal changes are no longer perceived, the sleep-wake rhythm is frequently disturbed. The short-term memory does not work, one’s own biography as well as the name of the spouse are mostly forgotten; Memories remain only patchy. Projects can hardly be realized. Parania, delusional disorders, anxiety and obsessive-compulsive symptoms, agitation and aggressive behavior previously unknown can occur. One speaks of moderate to severe dementia.
In stage 7 people are already talking of severe dementia, characterized by severe cognitive loss and complete dependence on help. The affected person seems to have no control over the body any onger able – smiling, speaking, walking, sitting, or keeping the head upright are virtually impossible. In this final stage the affected person eventually can no longer chew and swallow, breathing problems are increasing.