The average life expectancy after a person has been diagnosed with Alzheimer's is eight to 10 years, according to Healthline. However, this varies significantly among individuals. Factors that affect the life span of Alzheimer's patients are sex, overall health, brain abnormalities, gravity of symptoms and age at diagnosis.
After being diagnosed with Alzheimer's, women generally live longer than men do, states Healthline. Heart disease, diabetes and a history of heart attacks reduce the life span of Alzheimer's patients, as do brain and spinal cord abnormalities. Life expectancy is less for people whose motor skills have been severely affected. In addition, the younger the age at diagnosis, the longer the average life span.