Alzheimer’s disease is a progressive neurodegenerative disorder that primarily affects the brain, causing nerve cells to die and leading to impaired memory, thinking, and behavior. It represents the most common cause of dementia, accounting for approximately 60–80% of dementia cases. The disease is characterized by the accumulation of abnormal protein deposits in the brain, specifically amyloid plaques and neurofibrillary tangles, which interfere with normal cell function and lead to the loss of synaptic connections.
Effects on Thinking and Memory
Alzheimer’s disease significantly impacts a person’s ability to think and remember, with difficulty recalling recent events often being an early symptom. Individuals may struggle to form new memories, making it challenging to learn new information or recall recent conversations. This memory loss is more pronounced than typical age-related forgetfulness.
Beyond memory, the disease impairs problem-solving and planning abilities. Tasks that once seemed simple, such as managing finances, following a recipe, or organizing daily activities, become increasingly difficult and overwhelming. This decline in executive function can lead to compromised judgment and poor decision-making.
Language skills also suffer as the disease progresses, making communication more challenging. Individuals may experience trouble finding the right words, understanding conversations, or following complex instructions. This can lead to frustration and social withdrawal. Disorientation regarding time and place is another common cognitive effect, where individuals may get lost in familiar environments or become confused about the current date or season.
Changes in Behavior and Mood
Changes in behavior and mood are a significant aspect of Alzheimer’s disease, often stemming directly from alterations in the brain. Individuals may exhibit noticeable shifts in personality, becoming more withdrawn, irritable, or agitated. These changes are linked to the neurological damage.
Mood swings are common, with sudden shifts from a calm state to periods of agitation, anxiety, or even aggression. Depression and increased anxiety are also frequently observed as the disease progresses, affecting daily well-being. Some individuals may experience wandering, a tendency to move about aimlessly, which can pose safety concerns.
Paranoia, hallucinations, and delusions can also manifest, leading to a distorted perception of reality. For example, a person might believe that others are stealing their possessions or that unfamiliar individuals are living in their home.
Impact on Physical Abilities
As Alzheimer’s disease advances, particularly into its later stages, it begins to affect physical abilities. Individuals may develop difficulties with balance and coordination, increasing the risk of falls. This can lead to changes in their gait, making walking unsteady.
Motor skills, such as the ability to grasp objects or perform fine movements, also decline. Eventually, motor control declines, leading to a significant reduction in mobility, with some individuals losing the ability to walk independently. Basic bodily functions also become compromised.
Swallowing difficulties, known as dysphagia, can emerge, increasing the risk of aspiration pneumonia. Control over bladder and bowel functions may also be lost, leading to incontinence.
How Effects Progress Over Time
Alzheimer’s disease is a progressive condition, meaning its effects steadily worsen over time, leading to increasing dependency. The onset is often insidious, with initial symptoms easily mistaken for normal aging. The disease typically progresses through stages, starting with subtle cognitive changes and escalating to severe impairments across cognitive, behavioral, and physical domains.
In the early stage, memory loss, particularly of recent events, might be the most noticeable symptom, alongside some difficulties with planning or language. As the disease moves into the middle stage, cognitive impairments become more pronounced, with increased confusion, greater challenges in daily tasks, and the emergence of significant behavioral and mood changes like agitation or wandering.
The late stage of Alzheimer’s is characterized by severe cognitive decline, making individuals largely unresponsive to their environment and unable to communicate effectively. At this point, physical abilities significantly deteriorate, leading to loss of mobility, swallowing difficulties, and complete dependence on others for all aspects of daily care.