乌鸦传媒

Each type of dementia has its own disease trajectory. For Alzheimer's disease, the progression is predictable, although how long each phase lasts may differ from person to person.

The damage caused by Alzheimer's disease begins long before any symptoms show up. Over the course of years or decades in this preclinical stage, the characteristic buildup of disease-causing amyloid plaques and neurofibrillary tangles is underway. This can be seen in research studies with imaging tests or fluid biomarkers, but rarely is identified in normal medical care settings.

After some time, early symptomatic Alzheimer's disease begins with a small amount of memory loss and confusion that can be diagnosed as cognitive decline. While people may be able to function fairly normally in everyday activities of life during this stage, they may notice they are forgetting familiar words, misplacing objects, and starting to struggle with organizing, planning, socializing, and performing work tasks. Family and close friends may begin to notice these symptoms.

As the disease progresses to moderate dementia, damage in areas of the brain that control language, reasoning, conscious thought, and sensory processing lead to more severe symptoms.

Moderate Alzheimer's disease is characterized by increasingly poor memory and judgment, deepening confusion, getting lost, and mixing up who people are. Individuals in this stage generally need assistance with daily activities and caring for themselves, such as bathing, grooming, and using the toilet. Significant changes in personality and behavior are common, particularly paranoia and restless or agitated behaviors, especially late in the day (known as "sundowning"). Visual hallucinations and hearing things that aren't really there may occur as well. Some individuals have outbursts of aggressive physical behavior.

In the final stage, damage to the brain is so extensive that people with Alzheimer's disease struggle to communicate and may not know what is going on around them. Severe Alzheimer's disease typically requires full support for activities of daily life. Patients may need assistance with walking and as this stage advances, the body becomes rigid, and ability to swallow and control bladder and bowel function are lost.

Read previous installments in this series:

Part 1: For Your Patients: What Is Alzheimer's Disease?

Part 2: For Your Patients: How Is Alzheimer's Disease Diagnosed?

"Medical Journeys" is a set of clinical resources reviewed by doctors, meant for physicians and other healthcare professionals as well as the patients they serve. Each episode of this journey through a disease state contains both a physician guide and a downloadable/printable patient resource. "Medical Journeys" chart a path each step of the way for physicians and patients and provide continual resources and support, as the caregiver team navigates the course of a disease.