Alzheimer’s disease shortens life expectancy through a mix of disease progression and related health problems. On average, people diagnosed live three to twelve years, but this can drop to as little as three years or less in older patients due to factors like infections, poor nutrition, and other illnesses.
The disease itself advances at different speeds, leading to severe cognitive decline that makes daily tasks impossible. In later stages, many patients struggle with swallowing, which raises the risk of aspiration pneumonia, a common cause of death. Weight loss, dehydration, and malnutrition often follow as eating becomes harder, weakening the body further.
Other health issues speed up the decline. Heart disease, diabetes, and breathing problems make survival shorter by adding stress to an already fragile system. A history of falls, alcohol abuse, or low functional ability also cuts time down. Smoking and air pollution act as risk factors that worsen brain changes like inflammation and oxidative stress.
Age at diagnosis plays a big role. Younger people in their sixties might live seven to ten years after diagnosis, losing eight to thirteen years compared to healthy peers. Those diagnosed in their nineties often have just three years left. Men tend to have shorter survival than women, with gaps like five point seven years for men at age sixty five versus eight for women.
Disease features like greater cognitive impairment or neurological issues predict quicker end. Comorbidities and poor social factors, such as limited access to care, reduce life by nearly one year at age sixty five compared to those with better support.
Sources
https://int.livhospital.com/frontal-lobe-dementia-lifespan-essential-facts-for-caregivers/
https://en.wikipedia.org/wiki/Alzheimer’s_disease
https://www.oreateai.com/blog/understanding-life-expectancy-in-dementia-patients-key-factors-and-insights/f51ea8acc108f5a1dd22385f93f306fc
https://pubmed.ncbi.nlm.nih.gov/41447558/?fc=None&ff=20251225192832&v=2.18.0.post22+67771e2
https://www.oreateai.com/blog/understanding-life-expectancy-with-dementia-what-you-need-to-know/e680eb579227ef3417bf0505a625ff9b
