Ciwon Alzheimer cuta ce mai ci gaba, ɓarnawar ƙwaƙwalwa wacce ke shafar ƙwaƙwalwar ajiya, tunani, da ɗabi'a. Yana da alaƙa da mutuwar ƙwayoyin kwakwalwa a hankali, yana haifar da raguwar aikin fahimi da ikon yin ayyukan yau da kullun. Alamomin cutar Alzheimer yawanci suna daɗa tabarbarewa akan lokaci kuma suna iya haifar da rashin iya sadarwa, gane waɗanda ake ƙauna, da yin ayyuka na asali. Sunan cutar ne bayan Alois Alzheimer, wani likitan neuropathologist na Jamus wanda ya fara gano kuma ya bayyana yanayin a cikin 1906.