Résumé
Alzheimer's disease (AD) and Parkinson's disease (PD) are the primary diseases in neurodegenerative diseases. Nowadays, AD is common in one of the ten individuals whose age is more than 65, and its prevalence is kept on increasing with aging. Very few treatments and no effective treatments are available for curing neurodegenerative diseases. Pathogenesis of neurodegenerative diseases, Alzheimer's disease, Parkinson's disease, and their association with the nine hallmarks of aging were clearly described in this review. Instability in genomic, attrition in telomere, alterations in epigenetics, proteostasis loss, dysfunction in mitochondria, senescence in cells, sensing of deregulated nutrition, exhaustion of stem cells, and alterations in intercellular communication are the nine biological hallmarks of Aging. Improving the medical facilities for neurodegenerative diseases is very much essential. Doctors and researchers are doing surplus research to overcome the unavailability of proper treatments for such neurodegenerative diseases. Reason and the causes behind the diseases and their effects are explained in this review to enhance the further research to help the society.