“When it comes to the function of the human brain, there are a lot of unknowns,” says Suhag Patel, PA-C, certified physician assistant, UPMC Neurological Institute. “As a result, disorders of the brain may be hard to recognize or accept when they affect you or a loved one.”
The terms memory loss, dementia, and Alzheimer’s often are used interchangeably to describe older people who are living with cognitive impairment. These terms, however, describe three different conditions. Here’s what you need to know to tell them apart.
What’s the Difference Between Memory Loss, Dementia, and Alzheimer’s?
Memory loss that causes forgetfulness is a common part of the aging process and usually isn’t a sign of something serious. Age-related memory issues might be forgetting where you’ve put your keys or why you walked into a certain room.
But memory loss also may be a symptom of dementia and Alzheimer’s if it makes it hard for you to do everyday things. So while misplacing your keys is normal forgetfulness, not remembering how to drive home may be a sign of dementia or Alzheimer’s.
Dementia and Alzheimer’s aren’t the same condition, though many people confuse them.
Dementia is a broad term that describes a decline in a person’s mental ability. The National Institutes of Health (NIH) defines dementia as a loss of cognitive function — thinking, remembering, learning, and reasoning — to the point that it interferes with the person’s quality of life and daily activities.
People living with dementia may have problems with language skills, visual perception, or paying attention. Some may have personality changes.
There are many different forms of dementia. Alzheimer’s disease is one of them and is the most common form of dementia in people over age 65.
While the symptoms of Alzheimer’s and dementia overlap, a person can have a form of dementia that is not related to Alzheimer’s disease. However, everyone who has Alzheimer’s disease is considered to have dementia because Alzheimer’s is a form of dementia.
“Dementia and Alzheimer’s disease are not a normal part of aging and should be addressed by a doctor,” Suhag says.
What Is Dementia?
Dementia is caused by damage to brain cells that interrupts their normal function. Dementia is usually progressive, meaning that symptoms start out mild and get worse over time. Different types of dementia affect different areas of the brain and have different symptoms.
As a person’s brain cells are damaged, their mental functions decrease. For a condition to be diagnosed as dementia, at least two of the following functions must be severely impaired:
- Ability to focus or pay attention.
- Communication/language.
- Memory.
- Reasoning/judgment.
- Visual perception.
Doctors diagnose dementia by examining a person’s medical history and asking them and their family members about any changes in behavior or mental status. They also will:
- Evaluate a person’s cognitive skills, such as attention span and language.
- Order imaging tests such as CT, MRI, or PET scans to look for physical causes in the brain.
- Perform routine medical tests to rule out other causes.
Dementia may be caused by Alzheimer’s or another disease, or it may be the result of environmental or lifestyle factors, such as smoking.
What Is Alzheimer’s?
Alzheimer’s is a type of dementia that affects memory, thinking, language, and behavior. Most people diagnosed with Alzheimer’s are at least age 60 or older, although some may be diagnosed in their 40s or 50s. This is known as early-onset Alzheimer’s.
How Alzheimer’s Affects the Brain
The healthy human brain contains billions of neurons, specialized nerve cells that send signals between different parts of the brain and from the brain to the muscles and organs of the body. Alzheimer’s disease disrupts the communication among neurons, resulting in loss of neuron function and neuron death.
At first, Alzheimer’s just destroys neurons and their connections in parts of the brain involved in memory. Later, however, it affects other areas in the brain responsible for language, reasoning, and social behavior. Eventually, many areas of the brain are damaged.
Over time, persons with Alzheimer’s gradually lose their ability to live and function independently. Ultimately, the disease is fatal.
Stages of Alzheimer’s Disease
The disease varies for each person affected, but the general stages of its progression are:
- Normal behavior — Brain changes can begin as early as 10 years before diagnosis, although the person will show no symptoms.
- Mild mental decline — The person and their loved ones may notice subtle signs, such as forgetting words and names, repeating questions, or struggling with planning.
- Moderate mental decline — Memory issues may worsen. Affected people may start losing things, forgetting the date or time, ignoring personal hygiene, getting lost, or becoming flustered while doing everyday tasks.
- Severe mental decline — Those affected may not recognize people and may be unable to associate names with faces. They also may suffer from delusions, such as needing to go to a store that’s been out of business for years.
- Very severe mental and physical decline — In the end stages of the disease, the person will likely need help to eat, walk, and take care of themselves.
Is There a Cure for Dementia and Alzheimer’s?
“There is no cure for Alzheimer’s disease or dementia,” Suhag says.
Depending on the cause of dementia, however, doctors often can prescribe medicine to manage or slow down its symptoms. Though individuals can live with dementia for decades, it usually shortens lifespans.
Alzheimer’s is a terminal disease, but scientists are making great strides in identifying new ways to help diagnose, treat, and even prevent Alzheimer’s. Medicines can be prescribed to manage behavioral changes, memory loss, depression, and other symptoms. However, there is no way to stop the progression of the disease.
If you think you or a loved one may be affected by dementia or Alzheimer’s, make an appointment with your primary care provider.
Editor's Note: This article was originally published on , and was last reviewed on .