Many people with dementia who are elderly might not even live to the advanced stages — many will die from other causes such as heart failure, stroke, or accidents, and roughly a third of people with dementia will reach the more advanced stages and die in those advanced stages. For those who do reach the final stage, a critical issue is swallowing failure. When the part of the brain that coordinates swallowing becomes affected, food can go down the wrong way and cause pneumonia.