Home > Medical > Dementia > Alzheimer's Updated 21 June 2019 WATCH: What happens to the brain during Alzheimer's? Alzheimer's is one of the most common forms of dementia – but is also very much misunderstood. So, what happens to the brain during Alzheimer's? 0 Alzheimer's disease affects up to 50 million people worldwide. It's one of the most common forms of dementia in the world today. But it's also one of the most misunderstood medical conditions out there.Image credit: iStock Related articles WATCH: New study detects Alzheimer's up to 30 years before symptoms appear What if you could determine if you'll develop Alzheimer's, years in advance? How doing Sudoku and crossword puzzles could make your brain years younger New research supports previous findings that regular use of word and number puzzles helps keep our brains working better for longer. Scientists find 5 new genes that make people more vulnerable to Alzheimer's Learning more about how five gene variants influence Alzheimer's risk could improve knowledge on how the disease begins and provide potential new targets for drugs.