7.4M
Americans 65+ living with Alzheimer's in 2026
That is about 1 in 9 people age 65 and older, and the number is projected to reach nearly 13 million by 2050.
Source: Alzheimer's Association, 2026 Facts and Figures ↗The data · Brain health by the numbers
The science, quantified.
The numbers that frame the conversation, from how many people live with dementia to how often the brain is affected after surgery. Each figure links to where it comes from.
$409B
US health and long-term care costs for dementia in 2026
Medicare and Medicaid are expected to cover about 64% of these costs, which are projected to near $1 trillion by 2050.
Source: Alzheimer's Association, 2026 Facts and Figures ↗$818B
Total US cost of dementia in 2026, including unpaid care
This broader estimate adds unpaid family care, lost earnings and reduced quality of life to medical and long-term care costs.
Source: USC Schaeffer Center, via News-Medical ↗19B hours
Unpaid dementia care given by family and friends in 2025
Nearly 13 million Americans provide this care, valued at more than $446 billion.
Source: Alzheimer's Association, 2026 Facts and Figures ↗1 in 3
Older adults who die with Alzheimer's or another dementia
Alzheimer's was the fifth-leading cause of death among Americans 65 and older in 2024.
Source: Alzheimer's Association, 2026 Facts and Figures ↗~45%
Share of dementia cases potentially preventable or delayable
The 2024 Lancet Commission linked nearly half of cases to 14 modifiable risk factors, including hearing loss, high blood pressure, high LDL cholesterol and untreated vision loss.
Source: The Lancet Commission on dementia (2024), via UCL ↗40%+
Share of all surgical procedures performed on older adults
Older adults make up a large and growing share of people who receive anesthesia and surgery.
Source: American Society of Anesthesiologists, Brain Health Initiative ↗Up to 65%
Reported rate of postoperative delirium in older surgical patients
Delirium is the most common complication in older surgical patients; rates vary widely by type of surgery and patient, and programs like HELP can prevent many cases.
Source: Anesthesia Patient Safety Foundation ↗$26-42B
Estimated yearly US healthcare cost of delirium
A 2025 Medicare analysis of over 5.5 million surgical hospitalizations of adults 65+ also found documented postoperative delirium in about 1 in 30 cases.
Source: JAMA Network Open (2025), via News-Medical ↗1 in 5
Lifetime risk of Alzheimer's for a woman at age 45
For men at age 45, the estimated lifetime risk is about 1 in 10.
Source: Alzheimer's Association, 2026 Facts and Figures ↗The language of brain health
Understand the science.
The terms you'll see in the research, explained in a sentence or two.
Amyloid
A protein fragment that can clump into plaques between brain cells. Amyloid plaques are one of the defining features of Alzheimer's disease.
Biomarker
A measurable sign of a biological process, such as a protein level in blood or a pattern on a brain scan. Biomarkers help detect disease or track change over time.
Burst suppression
An EEG pattern where bursts of activity alternate with periods of near-silence. During anesthesia it can mean the brain is very deeply suppressed.
Cognitive reserve
The brain's ability to keep working well despite age-related changes or disease. Education, mental and social engagement, and physical activity are thought to help build it.
Delirium
A sudden change in attention, awareness and thinking that tends to come and go over hours or days. It is common in older adults after surgery or during serious illness and is often preventable.
EEG (electroencephalogram)
A painless recording of the brain's electrical activity using sensors on the scalp. It is used to study sleep, seizures, anesthesia and other brain states.
Mild cognitive impairment (MCI)
Noticeable changes in memory or thinking that are greater than expected for age but do not seriously affect daily independence. Some people with MCI stay stable, some improve and some go on to develop dementia.
Neuroplasticity
The brain's ability to change and form new connections throughout life in response to learning, experience and recovery from injury.
p-tau217
A specific form of tau that can be measured in blood. Higher levels are closely linked to Alzheimer's-related changes in the brain.
Perioperative neurocognitive disorder (PND)
An umbrella term for problems with memory and thinking linked to surgery and anesthesia, including delirium and longer-lasting changes once called postoperative cognitive dysfunction (POCD).
Processed EEG / depth of anesthesia monitoring
EEG signals analyzed by software and shown as simplified numbers or displays during surgery. Anesthesia teams can use them to help judge how deeply a patient is anesthetized.
Tau
A protein that normally helps support brain cells but can form tangles inside them in Alzheimer's. The spread of tau tracks closely with memory and thinking problems.
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Educational summaries of published research, each linked to its source. Not medical advice. Always talk to your doctor about your own health.