What are the causes of dementia?

Many causes: Some are heredity like huntingtons, early alzheimers, some are vascular with same risk as heart disease, others are due to infection (menigitits) or trauma (ie multiple head trauma), some related to auto immune disease. Clearly too many types to worry about. Eat healthy and exercise, get regular check-up and enjoy your brain now.

Multiple: Some dementia is ideopathic (i.e. Unknown) but other forms of dementia can be secondary to chronic disease (e.g. Huntington's), injury (e.g. Brain trauma), toxins (e.g. Chronic alcohol abuse) , or a nutritional deficiency (of b-12). Here's a good resource: http://goo.Gl/fce1c.

Many factors: such as inherited predisposition as in Alzheimer's Dementia , Vascular Dementia is caused by hardening of the arteries with decreased blood flow to the brain causing microvascular changes as in strokes, repeated blows to the brain as in those incurred in sports, boxing, football . Accidents causing concussions or traumatic brain injuries like explosions in war. Diseases like Parkinson's Disease