What Is Alzheimer’s Disease?

Reviewed by: HU Medical Review Board | Last reviewed: June 2019 | Last updated: March 2023

Dementia is a general term that encompasses symptoms having to do with memory impairment or cognitive decline severe enough to affect activities of daily living. Alzheimer’s disease is the most common cause of dementia and makes up 60-80 percent of dementia diagnoses.1,2

It is a progressive and irreversible brain disease that slowly eradicates memory and cognition. Eventually, the disease progresses to the point where it interferes with even the most basic functions of daily living like eating, talking, and movement.

With approximately 5.5 million Americans over the age of 65 having a diagnosis of Alzheimer’s disease, most individuals with the condition are older; however, more than 200,000 individuals in the United States are younger than 65 and are living with the disease.1,2

How was Alzheimer's disease discovered?

Dr. Alois Alzheimer first noticed brain tissue abnormalities in 1906, in a woman who died from mental illness and also reported memory loss, abnormal behavior, and issues with language.

Upon autopsy, Dr. Alzheimer noticed clumps and bundles of fibers in her brain – which are now referred to as amyloid plaques and neurofibrillary tangles, and are the hallmarks of the disease. The plaques are beta-amyloid protein deposits that have accumulated between nerve cells, and the tangles are twisted fibers of the protein called tau.1

Another aspect of the disease is the loss of communication between neurons, or nerve cells, in the brain. This makes it harder for the brain to send messages to various muscles and organs in the body, making it harder to carry out basic functions as the disease gets worse.

Symptoms of Alzheimer's disease

The symptoms of Alzheimer’s disease can vary, but the most common early symptom is trouble remembering just learned information.

Alzheimer’s usually originates in the area of the brain that has to do with learning, which is why this symptom is usually one of the first. Other symptoms can include disorientation, confusion that gets worse over time, behavior and personality changes, and trouble speaking, eating, and walking. These tend to get progressively more severe as time goes on and the disease progresses throughout the brain.

Treatment for Alzheimer's disease

While not curable or reversible, Alzheimer’s disease can be treated. Treatment focuses on slowing down progression of symptoms, maintaining mental and physical functions, and managing any behavioral symptoms that may arise. Lifestyle adaptations, caregivers, and various kinds of medications may all be used in treatment of Alzheimer’s disease. What treatment looks like can vary among individuals, depending on the most pressing symptoms and how severe they are. Sometimes comorbid medical conditions may be causing symptoms that mimic Alzheimer’s disease, so it’s important that the correct underlying cause is identified, as this will help determine the appropriate treatment.

Alzheimer’s disease may currently be incurable, but there is research being done for more effective treatments, better screening and diagnostic tools, and ways to better support caregivers and people living with the disease.

If you’ve recently been diagnosed, talk with your doctor about what that means for you right now, and what your next steps are. It can be overwhelming, but learning about your condition can help empower you to make informed choices about your treatment and better plan for your life and care.

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