Dementia isn’t a specific disease. Instead, dementia describes a group of symptoms affecting memory, thinking and social abilities severely enough to interfere with daily functioning.
Though dementia generally involves memory loss, memory loss has different causes. So memory loss alone doesn’t mean you have dementia.
Alzheimer’s disease is the most common cause of a progressive dementia in older adults, but there are a number of causes of dementia. Depending on the cause, some dementia symptoms can be reversed.
Dementia symptoms vary depending on the cause, but common signs and symptoms include:
- Memory loss, which is usually noticed by a spouse or someone else
- Difficulty communicating or finding words
- Difficulty reasoning or problem-solving
- Difficulty handling complex tasks
- Difficulty with planning and organizing
- Difficulty with coordination and motor functions
- Confusion and disorientation
- Personality changes
- Inappropriate behavior
When to see a doctor
See a doctor if you or a loved one has memory problems or other dementia symptoms. Some treatable medical conditions can cause dementia symptoms, so it’s important to determine the underlying cause.
Dementia involves damage of nerve cells in the brain, which can occur in several areas of the brain. Dementia affects people differently, depending on the area of the brain affected.
Dementias are often grouped by what they have in common, such as the part of the brain that’s affected or whether they worsen over time (progressive dementias). Some dementias, such as those caused by a reaction to medications or vitamin deficiencies, might improve with treatment.
Types of dementias that progress and aren’t reversible include:
In people age 65 and older, Alzheimer’s disease is the most common cause of dementia.
Although the cause of Alzheimer’s disease isn’t known, plaques and tangles are often found in the brains of people with Alzheimer’s. Plaques are clumps of a protein called beta-amyloid, and tangles are fibrous tangles made up of tau protein.
Certain genetic factors might make it more likely that people will develop Alzheimer’s:
Vascular dementia. This second most common type of dementia occurs as a result of damage to the vessels that supply blood to your brain. Blood vessel problems can be caused by stroke or other blood vessel conditions.
Lewy body dementia. Lewy bodies are abnormal clumps of protein that have been found in the brains of people with Lewy body dementia, Alzheimer’s disease and Parkinson’s disease. This is one of the more common types of progressive dementia.