**1. Introduction**

Past research has tried to find the pathogenesis and etiologies regarding Alzheimer's disease (AD). Recent studies show that reactive oxygen species (ROS) are linked with the progression and development of AD, especially superoxide anion, hydrogen peroxide, and hydroxyl radical. Reactive oxygen species have been found as the by-products of metal-catalyzed oxidation associated with amyloid-*β*. These findings are crucial for the treatment of AD, as they provide the underlying mechanism for metal chelation therapy, which involves the use of metal chelators for metal removal.

This chapter discusses both past and current research with regards to AD pathology and treatment in the following order: Alzheimer's disease, reactive oxygen species, oxidative stress and Alzheimer's disease, metal chelation therapy, and challenges of metal chelation therapy.
