Alzheimer's Disease and Dementia Fundamentals
What dementia is (and is not)
Dementia is an umbrella term for a decline in cognition severe enough to interfere with independence in daily life. Alzheimer's disease is the most common cause, but vascular dementia, Lewy body dementia, and frontotemporal dementia are distinct conditions with different trajectories. A key trap is treating "dementia" and "Alzheimer's" as synonyms, or assuming memory loss alone defines dementia-executive function, language, and visuospatial skills also decline.
Staging and trajectory
Know the broad stages: early (mild) stage with preserved independence but subtle memory and planning changes; middle (moderate) stage with increasing supervision needs, wandering risk, and communication difficulty; late (severe) stage with dependence in self-care and mobility decline. Questions often test that fitness programming must match the stage, not the calendar age.
Reversible and modifiable factors
Distinguish irreversible neurodegenerative disease from reversible contributors such as depression, thyroid dysfunction, B12 deficiency, medication side effects, and delirium (often triggered by infection or dehydration). A sudden change in cognition or function is a red flag for delirium or acute illness-not a cue to push harder in a session.
Risk and protective factors
Understand that physical activity is associated with reduced dementia risk and slower functional decline, but is not a cure. Vascular health (blood pressure, glucose, lipids), social engagement, and cognitive stimulation matter. Trap: questions implying exercise reverses Alzheimer's pathology.
Rule of thumb
If a client's function drops abruptly over days rather than months, assume a medical cause until cleared, and hold programming changes.
Worked example
A client who walked independently last month now needs a handrail and seems confused mid-session. Months-long decline suggests disease progression (adjust program); days-long decline suggests delirium (refer to clinician).