En español | From age 50 on, it’s not unusual to have occasional trouble finding the right word or remembering where you put things.
But persistent difficulty with memory, cognition and ability to perform everyday tasks might be signs of something more serious.
What is dementia?
Dementia isn’t actually a disease, according to the Mayo Clinic. It’s a catch-all term for changes in the brain that cause a loss of functioning that interferes with daily life. It can diminish focus, the ability to pay attention, language skills, problem-solving and visual perception. Dementia can also make it difficult for a person to control his or her emotions and can even lead to personality changes.
Roughly 6.5 million Americans are living with Alzheimer’s disease, the most common type of dementia, though many experts say that number is probably higher. And its prevalence is projected to reach nearly 13 million by 2050, according to a 2022 report from the Alzheimer's Association. Globally, over 55 million people have dementia, the World Health Organization estimates.
Diseases that cause dementia
These conditions are the leading causes of dementia. Many patients have mixed dementia, a combination of two or more types, such as Alzheimer’s and vascular dementia.
Alzheimer’s disease. Alzheimer’s is characterized by amyloid plaques and tangled fibers in the brain and by a loss of connections between nerve cells. Damage initially appears in the hippocampus, an area of the brain involved in memory formation, and gradually spreads.
Vascular dementia. The second most common type of dementia results from damage to the vessels that supply blood to the brain. It tends to affect focus, organization, problem-solving and speed of thinking more noticeably than memory.
Lewy body dementia. Abnormal protein deposits in the brain, called Lewy bodies, affect brain chemistry and lead to problems with behavior, mood, movement and thinking.
Frontotemporal disorders. Degenerative damage to the brain’s frontal and temporal lobes is the most common cause of dementia in people age 65 and younger. Symptoms might include apathy; difficulty communicating, walking or working; emotional changes; and impulsive or inappropriate behaviors.
Sources: National Institute on Aging, Mayo Clinic
If someone is showing signs of dementia, it’s important to see a medical expert who can conduct tests and come up with a diagnosis. Several, often treatable, conditions — from infections to a vitamin deficiency — can cause dementia-like symptoms, so it’s necessary to rule them out first.
If it is dementia, you’ll want to plan how you will manage care, especially as the condition progresses.
10 warning signs of dementia
Here are some symptoms to watch for:
1. Difficulty with everyday tasks. Everyone makes mistakes, but people with dementia may find it increasingly difficult to do things like keep track of monthly bills or follow a recipe while cooking, the Alzheimer’s Association says. They may also find it hard to concentrate on tasks, take much longer to do them or have trouble finishing them.
2. Repetition. Asking a question over and over or telling the same story about a recent event multiple times are common indicators of mild or moderate Alzheimer's, according to the Cleveland Clinic.
3. Communication problems. Observe if a loved one has trouble joining in conversations or following along with them, stops abruptly in the middle of a thought or struggles to think of words or the name of objects.
4. Getting lost. People with dementia may have difficulty with visual and spatial abilities. That can manifest itself in problems like getting lost while driving, according to the Mayo Clinic.
5. Personality changes. A loved one who begins acting unusually anxious, confused, fearful or suspicious, or who becomes upset easily and seems depressed is cause for concern.
6. Confusion about time and place. If someone forgets where they are or can’t remember how they got there, that's a red flag . Another worrisome sign is disorientation about time — for example, routinely forgetting what day of the week it is, says Jason Karlawish, M.D., a neurologist and professor of medicine at the University of Pennsylvania Perelman School of Medicine and codirector of the Penn Memory Center.
7. Misplacing things. Someone with dementia may put things in unusual places and may have difficulty retracing their steps to find misplaced items, the Alzheimer’s Association notes.
8. Troubling behavior. If your family member seems to have increasingly poor judgment when handling money or neglects grooming and cleanliness, pay attention.
9. Loss of interest. Not feeling especially social from time to time is one thing, but a sudden and routine loss of interest in family, friends, work and social events is a warning sign of dementia.
10. Forgetting old memories. Memory loss that becomes more persistent is often one of the first signs of dementia.
Some people who experience memory loss or have difficulty with attention, decision-making language or reasoning may have a condition known as mild cognitive impairment (MCI). The condition causes a noticeable decline, but the changes are less severe than with dementia and a person can still perform normal daily activities, according to the Cleveland Clinic.
People with MCI are at an increased risk of developing dementia.
Where to find help
When your loved one is displaying troubling symptoms, a trip to a primary care physician is often the first step. But to get a definitive diagnosis, you’ll need to see a specialist such as a neurologist, geriatrician or geriatric psychiatrist.
If you can’t find one, the National Institute on Aging recommends contacting the neurology department of a nearby medical school. Some hospitals also have clinics that focus on dementia.
Specialists will want to know about the patient’s medical history and habits (Do they exercise? Are they a smoker?) as well as their family medical history.
Recent research suggests that a prevalence among even members of your extended family can increase your dementia risk. And modifiable factors like high blood pressure, smoking, diabetes and insufficient physical activity can increase a person’s risk for dementia.
Doctors also will conduct physical and neurological exams to rule out other treatable causes for dementia symptoms.
Ailments Can Mimic Dementia
Any number of treatable conditions can cause dementia-like symptoms. Some of the most common:
• Alcohol abuse
• Anxiety, depression or stress
• Blood clots, brain infections or tumors
• Head injuries
• Kidney, liver or thyroid problems
• Side effects of medication
• Vitamin deficiencies
Source: National Institute on Aging
How is dementia diagnosed?
Some of the methods that doctors use to diagnose dementia:
• Cognitive and neuropsychological tests assess language and math skills, memory, problem-solving and other types of mental functioning.
• Blood tests are relatively new when it comes to diagnosing dementia and are still limited in clinical settings. Doctors can order one to measure levels of beta-amyloid, a hallmark of Alzheimer’s disease.
• Brain scans such as CT, MRI or PET imaging can spot changes in brain structure and function. These tests also can identify strokes, tumors and other problems that can cause dementia.
• Psychiatric evaluation can determine whether a mental health condition is causing or affecting the symptoms.
• Genetic tests are important, especially if someone is showing symptoms before age 60. The early onset form of Alzheimer’s is strongly linked to a person’s genes, according to the Mayo Clinic. Talk with a genetic counselor before and after getting tested.
Editor's note: This article, published on October 22, 2019, has been updated with more recent information.
Patrick J. Kiger is a contributing writer for AARP. He has written for a wide variety of publications, including the Los Angeles Times Magazine, GQ and Mother Jones, as well as the websites of the Discovery Channel and National Geographic.