Risk factors for developing dementia include a family history of dementia, Down syndrome and old age, according to Mayo Clinic. Other risk factors include alcoholism, smoking, atherosclerosis and obesity.
Senile dementia is an obsolete phrase previously used by those describing memory loss and confusion they thought was a normal part of aging rather than the side effect of a disease such as Alzheimer's, explains Alzheimer's Society.
There are two varieties of dementia: progressive dementia and reversible, dementia-like conditions, according to Mayo Clinic. Progressive dementia includes Alzheimer's disease, vascular dementia, Lewy body dementia and frontotemporal dementia. Conditions that manifest reversible dementia-like symptoms include heavy metal poisoning, subdural hematomas, dehydration and vitamin B-1 deficiency.