Lack of oxygen to the brain(due to stroke, transient ischemic attack (TIA), heart attack, respiratory problems, and carbon monoxide poisoning)
Malnutrition(e.g., lack of thiamin [vitamin B-1] or vitamin B-12)
Medicationsand drug interactions
Normal pressure hydrocephalus(NPH; excessive buildup of fluid in the brain can increase pressure and squeeze brain tissue)
Overactive or underactive thyroid gland
Wilson's disease(results in too much copper in the body, which can cause brain damage)
Risk factors for amnesiainclude brain trauma (e.g., surgery, head injury), stroke, and excessive alcohol use. Risk factors for mild cognitive impairment (MCI) include high blood pressure (hypertension) and diabetes. People with lower levels of education, physical and mental exercise, and socialization, and people with a mutation of the APOE (apolipoprotein E) gene also are at higher risk for developing memory problems.