According to Columbia University, almost 10% of US adults over 65 have dementia, while another 22% have mild cognitive impairment. In this article, Ability Central will share quick facts about what dementia is and what you need to know about it, including:

• What is the difference between dementia and Alzheimer’s?
• What causes dementia?
• What are the types of dementia?
• What are the risk factors for dementia?
• Where can I get more information about dementia?

What is the difference between dementia and Alzheimer’s?

Dementia is not a specific disease but rather a general term that encompasses loss of memory, language, problem-solving, and other thinking abilities. It is a group of symptoms caused by other conditions.

Alzheimer's is the most common form of dementia. It may contribute to about 60-70% of all dementia cases.

Dementia is currently the seventh leading cause of death among all diseases. It is one of the major causes of disability and dependency among older people.

While most changes in the brain that cause dementia are permanent and worsen over time, some diseases mimic dementias and might improve with treatment.

What causes dementia?

Dementia happens when the parts of your brain used for learning, memory, decision-making, and language are damaged or diseased. The brain is made of distinct regions. Different regions are responsible for distinct functions. When cells in a particular area are damaged, that region may not function normally.

To learn more about the effects dementia has on day-to-day activities, see Dementia: Warning Signs and Symptoms.

What are the types of dementia?

Dementias are often grouped by what they have in common or the part of the brain that is affected. 

The five types of dementias that progress and aren't reversible include:

1. Alzheimer's disease. People with Alzheimer's disease have clumps of a protein called beta-amyloid and tau protein tangles. It's thought that these clumps damage healthy neurons and the fibers connecting them.
2. Vascular dementia is caused by damage to the vessels that supply blood to your brain.
3. Lewy body dementia results from abnormal balloon-like clumps of protein collecting in the brain.
4. Frontotemporal dementia is a group of diseases characterized by the breakdown of nerve cells and their connections in the frontal and temporal lobes of the brain. 
5. Mixed dementia is a condition in which brain changes of more than one cause of dementia co-occur.

Depending on the damaged area of the brain, dementia can affect people differently and cause different symptoms. To learn more about the stages, signs, and symptoms of dementia, see Dementia: Warning Signs and Symptoms.

What are the risk factors for dementia?

Some risk factors for dementia are beyond a person’s control. For example, while dementia is not a normal part of aging, the risk for dementia rises with age. In addition, having a family history of dementia puts you at greater risk of developing the condition. 

However, other risk factors for dementia are within your control. They include:

• High blood pressure
• Smoking
• Type 2 Diabetes
• Obesity
• Lack of physical activity
• An unhealthy diet high in saturated fat, sugar, and salt
• Drinking more than 14 alcoholic drinks per week for women and more than 21 alcoholic drinks per week for men
• Low levels of cognitive engagement
• Depression in mid- or later life
• Severe or repeated head injuries
• Communication impairments, like hearing loss or other communication disabilities 
• Social isolation
• Air pollution

Dementia and Alzheimer’s Disease

Dementia is a general term used to describe a loss of memory and other cognitive abilities that interfere with daily life and a person’s ability to communicate. Alzheimer's disease is a specific type of dementia that gradually worsens over time. It is a physical illness that damages the brain, leading to symptoms of dementia. While Alzheimer's disease is the most common form of dementia, there are many other types as well. However, it is important to note that not all dementia is caused by Alzheimer's disease.

Learn more about Alzheimer’s disease. 

Where can I get more information about dementia?

Ability Central has multiple resources to learn more about dementia, including:

• Dementia: Warning Signs and Symptoms
• Dementia: What to Do After Receiving a Diagnosis
• Dementia: Planning for Long-term Care