Dementia is a broad term that describes a loss of thinking ability, memory and other mental abilities.  About 5-8% of adults over 65 have some form of dementia and their percentage doubles every 5 years after 65.  

Some symptoms include:

• Short-term memory problems, like forgetting where you put something or asking the same question over and over
• Communication problems like not being about to come up with a word
• Getting lost
• Trouble with complex but familiar tasks, like fixing a meal or paying bills
• Personality changes, like depression, agitation, paranoia, and mood swings

About 20% of the causes of dementia may be reversible and include:

• Depression
• Alcohol or drug abuse
• Tumors
• Subdural hematomas, blood clots beneath the outer covering of the brain
• Normal-pressure hydrocephalus, a buildup of fluid in the brain
• Metabolic disorders such as a vitamin B12 deficiency
• Low levels of thyroid hormones, called hypothyroidism
• Low blood sugar, called hypoglycemia
• HIV-associated neurocognitive disorders

The other forms of dementia are partially manageable, although not reversible, but there are drugs that are purported to slow the progression of memory loss and manage symptoms:

• Alzheimer’s disease
• Vascular dementia
• Dementia from Parkinson’s disease and similar disorders
• Dementia with Lewy bodies
• Frontotemporal dementia
• Creutzfeldt-Jakob disease