how long does a person with ad usually live
AD starts long before there are symptoms (according to studies), so that question is not really one that can be answered. But after symptoms occur, it still is different for everyone. Some people live five years, others twenty. Much as to do with general health, but in some cases, there seems to be no real explanation.
I agree with Carol. My maternal grandmother (who had undiagnosed dementia and who was physically always healthy) ended up living with the disease for almost 10 years. On the other hand, my mom (who had Chronic Obstructive Pulmonary Disease from smoking for about 50 years) was officially diagnosed with Alzheimer's in 2005 and died in 2007 (although she had started experiencing noticeable memory loss in 2003/2004). And Mom's death was caused by pneumonia due to her weakened lungs. So other health issues can play a large part in how long a person with Alzheimer's will live.
Take care and keep us posted!
Like what Carol and Dorian mentioned, no one is the same.
I would like to point out that, if the person with AD can live to the last minute without any other major diseases, the end stage usually lasts 1 to 3 years. But it takes a long time to reach that end stage. Some people did and it took 10 years or more.
For example, my father-in-law who has late mid-AD also has heart failure this year and it would only give him 5 more years due to the heart problem.
I found some website that tells me that early AD may take 4 or more years to be diagnosed, and that mid-AD could last 3-10 years and is the longest of all stages. Only the end stage is very clear and even that takes 3 years at most. It goes by a long shot really.
My FIL has had AD since Nov. 2006. His friend suspected that he had AD in 2004. He is 88 now and I think he got it when he was 80 or so. No one knows when it starts at all.
Not to mention the causes.