Disorientation is most often seen in various organic psychiatric disorders. Often considered one of the symptoms of organic syndromes, it is also seen in people with mental retardation, such as Alzheimer’s disease and mental retardation, as well as functional neuropathies and neurocongenital disorders. As well as the possibility of abnormal brain development, it is also important to be aware of the possibility of accompanying other causes, such as infections, fatigue and other factors that cause the effects. Causes of Alzheimer’s disease I. Genetic factors AD has a family aggregation, about 20% of patients have a positive family history, and their first-degree relatives have a great risk of disease. Molecular biology studies have demonstrated that there are abnormal gene loci on chromosomes 21, 19, 14, and 1. The proteins encoded by these affected genes are β-amyloid (β-AP), apolipoprotein E (ApoE), progerin-1 (PS-1), and progerin-2 (PS-2). Mutations and polypeptide alterations in these genes have been associated with AD pathogenesis. β-AP is produced by abnormal cleavage of the β-amyloid precursor protein (β-APP) and is a major component of age spot formation. the Apo E gene is one of the most important genetics influencing the aging pathway, and the risk of both late-onset familial AD and sporadic AD occurrences is dependent on the Apo E4 The risk of both late familial AD and sporadic AD is dependent on the amount of the Apo E4 allele. Second, neurotransmitter theory The transmitter alterations associated with AD are the acetylcholine system, the monoamine system, amino acids and neuropeptide transmitters, of which the reduction of choline acetyltransferase and acetylcholine transmitters is an important cause of AD. Neuropharmacological studies have confirmed that AD patients have reduced acetylcholine transferase activity in the cortex and hippocampus, which directly affects the synthesis of acetylcholine and the function of the cholinergic system. In addition, AD patients without growth inhibitor, adrenocorticotropic releasing factor and norepinephrine are significantly reduced, dopamine hydroxylase activity are significantly reduced. Third, viral infection Experiments have proved that the virus that deforms the brain tissue of sheep can appear typical age spots when inoculated in the brain of mice. In vitro experiments show that herpes virus infection can reduce the level of acetylcholine transferase in chromophobe PC12 cells. This suggests that viral infection may be one of the causes of this disease. Fourth, the role of metal part of the AD patients brain aluminum concentration up to 10-30 times the normal brain, age spots (SP) core aluminum deposition, sneak attack to dementia can also be seen in the brain aluminum increase, therefore, it is presumed that aluminum is related to dementia. But aluminum is the cause or result of dementia is not very clear. V. Immune dysfunction and free radical damage Immune dysfunction and free radical damage are related to the development of AD, and the brain reactive antibody of AD is 20% higher than that of the control group, which indicates that the autoantibody content of patients with this disease is increased, and it may play a role in the disappearance of neurons and aging.