The greatest risk factor for dementia is advanced age. Inheriting the genes associated with Alzheimer's or Huntington's disease is a risk factor. Untreated infectious and metabolic disease and substance abuse also can lead to dementia.
Other risk factors include the following:
- Brain tumor
- Cardiovascular disease (e.g., high blood pressure, high cholesterol, atherosclerosis)
- Head injury
- Kidney failure, liver disease, thyroid disease
- Vitamin deficiencies: B12, folic acid, B1 (thiamine)