Alzheimer’s disease is the most common type of type of dementia — a condition that causes ongoing problems with thinking, remembering, and behavior. These changes in the brain happen slowly, usually over four or more years in people older than 65. While everyone forgets things or behaves differently on occasion, people with Alzheimer’s disease experience these changes more often, and the changes are serious enough to impact daily life.
Those who may have some trouble remembering but can still do normal daily activities on their own have mild cognitive impairment (MCI). Sometimes a person’s MCI gets worse and becomes Alzheimer’s disease. Sometimes, it gets better or doesn’t change at all.
Symptoms of Alzheimer’s disease are progressively worsening changes in a person’s memory, judgment, and reasoning that are severe enough to interfere with their independence and daily activities. For example, people with dementia may:
- Ask the same question or repeat the same story over and over
- Get lost in familiar places
- Struggle to follow simple or familiar directions (like how to work the microwave)
- Experience troubling behavior changes (like becoming agitated or aggressive)
- Get confused about time, people, and places
- Neglect personal safety, nutrition, and bathing
Early in the disease, a person won’t feel “sick” but may experience behavior and personality changes such as: irritability, anxiety, or depression. As the disease progresses, more severe behavior and personality symptoms may include:
- Anger, agitation, or aggression (including physical or verbal outbursts)
- General emotional distress, restlessness
- Hallucinations or delusions
- Difficulty sleeping and dramatic changes in the sleep-wake cycle
We do not know exactly what causes Alzheimer’s disease. What we do know is that those with the disease develop a type of plaque (beta amyloid) deposit in their brains as well as disorganized masses of protein fibers (neurofibrillary tangles). These cause a loss of connections between nerve cells (neurons) in the brain. As nerve cells die, the brain begins to shrink, and the person increasing loses control of the simplest of daily functions.
Scientists have identified several risk factors for getting Alzheimer’s disease, including:
- Age. Alzheimer’s disease is rare before age 60 and very common in those over age 80.
- Family history. Having a parent or sibling with Alzheimer disease increases the risk, especially if the family member developed the disease before age 70.
- Having a particular gene, called APOE epsilon 4, may increase a person's risk. Research to date has not established this gene as a definite cause.
Other possible risks include having high blood pressure or diabetes, smoking, and lifestyle factors (being physically inactive, not being socially connected or mentally engaged).
There is currently no definitive blood test or imaging study (like an MRI or CT scan) that tells your doctor that you have Alzheimer’s disease. Instead, your doctor and other specialists will gather information from several sources before diagnosing Alzheimer’s disease including:
- Performing a screening memory test (called a “Mini-Cog”) and a follow-up test (called “MoCA”)
- Asking you and your family or friends about life at home — are there things that you could once do easily but now struggle with
- Ordering some lab tests or reviewing recent ones you've had
- Suggesting getting an MRI or CT scan of your brain
- Referring you to a specialist, like a neurologist or neuropsychologist, for more detailed memory testing
There is currently no cure for Alzheimer’s disease; however, some medicines can help with certain symptoms and slow down the process for a period of time. These medicines work by affecting certain chemicals involved in carrying messages among the brain's nerve cells.
Non-drug strategies, which should always be tried before medicines for Alzheimer’s symptoms, can help promote physical and emotional comfort. These non-drug strategies can help:
- Manage medical conditions that can make memory worse, such as:
- Untreated thyroid disease
- Vitamin B12 deficiency
- Heart failure
- Obstructive sleep apnea
- High cholesterol
- High blood pressure
- Kidney failure
- Drug and alcohol use
- Go to all healthcare appointments so that your doctor can monitor how you are doing and support your needs.
- Develop a self-care plan for managing medicines, diet, exercise, safety, and planning for the future.
- Ask for support from family and friends about the diagnosis and what you want for your care and living situation in the years to come.
- Access local support groups and online resources.
Those with Alzheimer's disease live an average of eight years after their symptoms become noticeable to others. However, they can live from four to twenty years after diagnosis based on their age and other medical conditions they might have.
Although Alzheimer’s disease is the 6th leading cause of death in the U.S., most people do not die from the disease itself. They tend to die as a result of a pneumonia, bladder infection, or complications of a fall.
- Alzheimer's Disease Education and Referral (ADEAR) Center (National Institute on Aging)
- National Institute of Neurological Disorders and Stroke
- Administration on Aging (Department of Health and Human Services)
- The American Geriatrics Society
- Alzheimer's Association, which offers helpful online resources: