Amnesia is the loss of memory due to various factors that affect the healthy cognitive functioning of the brain. The study of amnesia is essential to the understanding of the brain functioning and the different parts of the brain that control memory. This paper provides detailed research into amnesia starting with the history of amnesia, which can be traced back to a patient named Henry Molaison. It also shows the normal cognitive functioning of the brain, a condition in which it can process information quickly and stores both short-term and long-term memory. The study provides a more in-depth insight into the disease by explaining the two types of amnesia. The first is anterograde amnesia a situation in which the brain cannot form new memories. Retrograde amnesia is a condition in which the brain loses its normal ability to retrieve information about events that happened before the onset of amnesia. The paper outlines the various causes of amnesia. They include traumatic brain injury, hypoxic ischemia, intracranial surgery that is the surgical process of treating temporary lobe epilepsy and cancer, which damages the hippocampus. Stress is also explained as a causative factor in the development of amnesia. The study provides current research in which amnesia can be caused by biological forces and not through detectable brain damage through the process of dissociation. The paper proposes a new area of study, which is the effect of approaches of preventing amnesia.