Alzheimer’s disease (AD), initially identified by Alois Alzheimer in 1907, is a leading cause of dementia in the elderly population globally. Dementia affects approximately 0.7% of the world’s population, with Japan having the highest prevalence (3079 cases per 100,000). By 2040, dementia-related deaths are projected to rise from the current 2.4 million per year to 5.8 million. Females are more prone to developing dementia than males. This disease is linked to the accumulation of amyloid plaques and neurofibrillary tangles in the brain, leading to gradual memory deterioration and cognitive dysfunction. Pathophysiological research has focused on understanding molecular abnormalities, such as brain amyloidosis, tau accumulation, and neuroreceptor changes, which are crucial for early diagnosis and disease monitoring. Diagnosis involves screening measures, such as the MMSE, as well as biomarker testing, such as cerebrospinal fluid biomarkers and positron emission tomography (PET). The objective of this chapter is to gain insight into the molecular irregularities that underlie Alzheimer’s disease, including early detection and encouraging therapies, with the ultimate goal of providing hope for millions of people affected by the condition on a global scale. Currently, the treatment of AD is limited to two pharmaceutical classes: N-methyl-d-aspartate (NMDA) antagonists and cholinesterase inhibitors. However, alternative treatment approaches targeting biochemical pathways, such as the inhibition of β-secretase and glycogen synthase kinase-3β, are being explored to combat this debilitating disease.