What Is Dementia?
Dementia is a decline or loss of reasoning, memory, and other mental abilities (the cognitive functions such as judgment, thinking, behavior, and language) and is not a normal part of aging. This decline is progressive and eventually impairs the ability to carry out everyday activities such as driving; household chores; and even personal care such as bathing, dressing, and feeding (often called activities of daily living).
According to World Health Organization (WHO) statistics, about 47 million people worldwide have dementia, with a projected increase to 75 million by 2030 with nearly 10 million new cases each year.
What Causes Dementia?
Dementia is caused by damage to or changes in the brain.
Common causes of dementia are:
- Alzheimer’s disease. This is the most common cause of dementia.
- Vascular dementia. This may occur in people who have long-term high blood pressure, severe hardening of the arteries, or several small strokes. Strokes are the second most common cause of dementia.
- Parkinson’s disease. Dementia is common in people with this condition.
- Dementia with Lewy bodies. It can cause short-term memory loss.
- Frontotemporal dementia. This is a group of diseases that includes Pick’s disease.
- Severe head injury.
Less common yet causes of dementia include:
- Huntington’s disease.
- Leukoencephalopathies. These are diseases that affect the deeper, white-matter brain tissue.
- Creutzfeldt-Jakob disease. This is a rare and fatal condition that destroys brain tissue.
- Some cases of multiple sclerosis (MS) or amyotrophic lateral sclerosis (ALS).
- Multiple-system atrophy. This is a group of degenerative brain diseases that affect speech, movement, and autonomic function.
- Infections such as late-stage syphilis. Antibiotics work well to treat syphilis at any stage, but they can’t reverse the brain damage already done.
Some disorders that cause dementia can run in families. Doctors often suspect an inherited cause if someone younger than 50 has symptoms of dementia.