Alzheimer's disease tends to progress, deteriorate and lead to death within 2 to 15 years. However, the progress of the illness varies a lot between individuals. For some, the illness may progress slowly over many years, whereas for others it may progress rapidly.
A number of other treatable medical conditions can mimic Alzheimer's disease. These include thyroid problems, infections, vitamin deficiencies, depression and anxiety. It is vital that any elderly person who is concerned about whether they may be getting Alzheimer's disease sees their family doctor and receives a full medical assessment.
Never assume that an old person who becomes forgetful will have Alzheimer's disease. For the majority of old people, forgetfulness is simply a nuisance, and some does not develop Alzheimer's disease. But this is the FIRST sign of Alzheimer's disease.