Alzheimer’s disease is a disease that damages and ultimately destroys brain cells, leading to:
- Memory loss
- Trouble thinking clearly
- Loss of social skills
The condition can also lead to:
- Poor judgment
- Confusion and disorientation
- Changes in personality
- Delusions
- Forgetting how to read or write
When these changes get severe enough to get in the way of day-to-day life, they are known as dementia. Alzheimer’s disease is the most common cause of dementia, accounting for 3 to 4 out of every 5 people with dementia—but it is not the only cause.
Other conditions that cause dementia include:
- Parkinson’s disease and dementia with Lewy bodies, caused by buildup of a specific protein in the brain
- Genetic conditions such as Huntington’s disease and frontotemporal dementia
- Prion diseases, such as Creutzfeldt-Jakob disease and mad cow disease
- Physical problems inside the brain, such as brain tumors, vascular dementia, and normal pressure hydrocephalus
- Wernicke-Korsakoff syndrome, a memory disorder that often affects heavy drinkers
When a person has more than one of these conditions, it is called mixed dementia. Dementia can also be caused by:
- Side effects of medication
- Infections
- Some toxins
- Oxygen shortage in the brain, known as hypoxia
Many types of dementia cannot be cured, although some have treatments that can alleviate symptoms or slow the progression of the disease. Alzheimer’s disease affects more than 5 million Americans, about half of who don’t know they have the condition. Other types of dementia are harder to estimate, but may affect an additional 1.3 to 3.5 million people in the United States.
