Alzheimer's disease (AD), a multifaceted neurological ailment that progresses over time, is the most common cause of dementia in older people. Intracellular neurofibrillary tangles and extracellular amyloidal protein deposits contribute to senile plaques on a pathological level. AD symptoms vary depending on the stage of the disease. Depending on the severity of cognitive impairment, AD is classified as preclinical or presymptomatic, mild, or dementia-stage. In addition, the condition is influenced by a number of risk factors, including advancing age, hereditary factors, head injuries, vascular diseases, infections, and environmental variables. There are currently only two types of licenced medications to treat AD: inhibitors of the cholinesterase enzyme such as donepezil, rivastigmine, galantamine and antagonists of N-methyl d-aspartate (NMDA) such as memantine, both of which are only effective in treating the symptoms of the disease and do not cure or prevent it.