How Common Is Alzheimer's Disease?

Alzheimer's disease is a type of brain disease that causes difficulty remembering things, confusion, and behavioral changes. Alzheimer’s disease is the most common type of dementia. Between 60 and 80 percent of dementia cases are caused by Alzheimer’s disease.^1,2

How many people have Alzheimer's disease?

Experts estimate that about 6.9 million Americans older than 65 have Alzheimer’s disease. This means about 1 in 10 Americans over age 65 have the condition. As people age, their chance of developing Alzheimer’s disease increases.^1,2

The percentages of people who have Alzheimer’s disease in certain age groups are:^1,2

• About 5 percent of people aged 65 to 74
• About 13 percent of people aged 75 to 84
• About 33 percent of people older than 84

Who is more likely to get Alzheimer's disease?

Certain factors can make certain groups more likely to develop Alzheimer’s disease. This includes an increased incidence of Alzheimer’s disease in women and people of color.^1-3

For women, the chance of developing Alzheimer's disease in their lifetime is about 1 in 5. For men, this chance is about 1 in 10. However, women on average live longer than men, and old age is the biggest risk factor for dementia. When adjusting for life span, it does not seem that women are more likely to develop Alzheimer's disease than men of the same age.^1,2

Rates of Alzheimer’s disease are different for different races in the United States. Black and Hispanic older adults are most likely to develop Alzheimer’s disease. About 19 percent of Black and 14 percent of Hispanic adults over age 65 have some kind of dementia. About 10 percent of white adults over age 65 have some kind of dementia.^1-3

This link is likely due to increased risk factors rather than genetic differences. In the United States, people of color are more likely to experience factors like poverty, exposure to pollution, and lower quality healthcare. These can all increase their risk of developing dementia.^1-3

What are the risk factors for Alzheimer's disease?

There are several risk factors linked to Alzheimer’s disease. However, more research may be needed to confirm some of these links. Risk factors for Alzheimer’s disease may include:^1-3

• Old age – Risk of Alzheimer’s disease increases with age.
• Family history – The risk of getting Alzheimer’s increases if a parent or sibling has it. Experts do not fully understand the reason for this link or how it impacts the risk.
• Down syndrome – People with Down syndrome are more likely to develop Alzheimer’s disease. Their symptoms also are more likely to develop earlier.
• Head trauma – A history of a traumatic brain injury (TBI) increases the risk of dementia, including Alzheimer's disease. The risk is even higher with multiple TBIs.
• Excessive alcohol drinking – Heavy drinking has a strong link to early-onset dementia.
• Air pollution – People exposed to high levels of air pollution may have increased dementia risk. Air pollution can come from sources like car exhaust or burning wood.
• Lifestyle factors like poor sleep, obesity, or smoking – Adopting healthy lifestyle habits may lower your risk of Alzheimer’s disease. These can include eating a healthy diet, exercising regularly, and developing good sleep habits.

Even if certain risk factors apply to you, you will not necessarily develop Alzheimer’s disease. If you are concerned about your risk for the disease, talk with your doctor. They may be able to assess your risk or offer preventative measures.^1,2