Mild cognitive impairment (MCI) is a neurological disorder characterized by cognitive impairment that is greater than expected for a person's age and education level, but not severe enough to interfere with basic daily activities. MCI may occur as a transitional stage between normal aging and dementia, particularly Alzheimer's disease. This disorder includes both memory-related and non-memory-related manifestations. The cause of MCI is still not clearly known, and its prevention and treatment are equally unknown. MCI can present with a range of symptoms, but it is mainly divided into two types: According to some experts, MCI can result from brain changes induced during the early stages of Alzheimer's disease and other forms of dementia. However, the direct causes of this disorder are still unclear. The risk factors for MCI are the same as those for dementia: aging and the genetic cause of Alzheimer's disease or senility, in addition to another risk factor, cardiovascular disease. In patients with mild cognitive impairment, increased oxidative DNA damage was observed in the nuclei and mitochondria of brain neurons. Increases in 8-hydroxyguanine, a substance known to cause DNA damage, were found in the frontal and temporal lobes of patients with mild cognitive impairment and in mitochondrial DNA of the temporal lobe compared with age-matched controls. The number of oxidized DNA bases was increased in the brains of patients with this disorder. These findings suggest that oxidative DNA damage occurs in the earliest diagnosable stages of Alzheimer's disease and may therefore play an important role in the study of the pathogenesis of this disease. The diagnosis of mild cognitive impairment requires expert clinical judgment, in addition to a detailed clinical evaluation that includes clinical approach, neuroradiology, blood tests, and neuropsychological evaluation to rule out alternative differential diagnoses. Mild cognitive impairment is diagnosed when: There is evidence that people with mild cognitive impairment with amnesia may be in the transitional phase of Alzheimer's disease even though they do not meet the neuropathological criteria for a diagnosis of Alzheimer's disease; people in this presumed transitional phase have widespread amyloid deposits in the neocortex and neurofibrillary tangles in the medial temporal lobe. On the other hand, many people develop neurofibrillary tangles without amyloid, a pattern called primary age-related tauopathy. There is emerging evidence that MRI can detect degeneration, including progressive loss of gray matter in the brain, ranging from mild cognitive impairment to overt Alzheimer's disease. An imaging technique known as Pittsburgh B positron emission tomography is used to visualize areas of beta-amyloid peptide in living specimens using a radiocarbon marker that selectively binds to these deposits. 18F positron emission tomography (PET) using florbetapine is a promising method for predicting the future progression of mild cognitive impairment to Alzheimer’s disease dementia, but further study is needed to prove the diagnostic test’s accuracy in larger trials. These methods could be of great help in facilitating clinical research into treatments. The prevalence of mild cognitive impairment varies by age. The prevalence of the disorder in several age groups is as follows: 6.7% in 60-64 age groups, 8.4% in 65-69 age groups, 10.1% in 70-74 age groups, 14.8% in 75-79 age groups, and 25.2% in 80-84 age groups. After two years of follow-up, the overall prevalence of dementia among people with mild cognitive impairment aged 65 and over appears to be 14.9%. Globally, about 16% of the world’s population over the age of 70 has some form of mild cognitive impairment.