Mixed dementia happens when more than one type of dementia is present at the same time. The most common combination is Alzheimer’s disease and vascular dementia, meaning a person has both plaques and tangles from Alzheimer’s and reduced blood flow damage from vascular dementia. This mix can cause a faster decline and make symptoms less predictable—some days may seem better than others, and symptoms may fluctuate. Since mixed dementia isn’t always recognized during life, many people diagnosed wit