Alzheimer’s disease is an incurable form of dementia that affects memory and cognitive functions over time. The condition is the sixth leading cause of death in the United States and the fifth leading cause of death among those age 65 and older.

The number of people dying from the disease has significantly increased over the years. The annual Alzheimer’s death rate has more than doubled, from 17.6 deaths per 100,000 residents in 2000 to 37.3 deaths per 100,000 residents in 2018, according to data from the National Center for Health Statistics. There are several possible explanations for the increase, including a growing proportion of older adults, increased diagnosis of Alzheimer’s, and increased reporting of the disease as a cause of death by doctors.

The number of people developing Alzheimer’s is projected to increase by at least 6.7% in every state between 2020 and 2025 in the U.S., according to the Alzheimer’s Association.

24/7 Tempo reviewed the Alzheimer’s Association Facts and Figures to determine the states where Alzheimer’s causes the most deaths per capita. The death rate due to the disease ranged from 17.8 to 53.5 per 100,000 residents.

The biggest risk factor for developing Alzheimer’s is age. The risk doubles every five years after age 65. Nearly one in three people aged 85 and older are at risk. Only one of the 15 states with the highest share of Americans with Alzheimer’s has a lower share of the population that is 85 or older than the national average of 1.9%. The share of the population 65 and older in all of those 15 states is higher than the national average of 16.5%.

After being diagnosed, adults who are older than 65 survive on average between four and eight years, but this can range significantly depending on lifestyle and certain pre-existing conditions. These include smoking, high blood pressure, and high cholesterol levels.

Another possible factor may be depression, though the connection between depression and Alzheimer’s is not fully understood. A study published in the Nature Reviews Neurology journal found that people who became depressed late in life are at a greater risk of developing dementia. But depression is also very common among people with Alzheimer’s.

Scientists have been researching the disease for decades. One of the main findings is the buildup of two abnormal structures — beta-amyloid plaques and tangles of a protein called tau — in the brains of people with Alzheimer’s disease. These are suspected in damaging and killing nerve cells.

There are some measures that a person can take to reduce the risk of Alzheimer’s. Some research suggests that regular exercise can reduce the risk by as much as 45%. Even just a walk a day may help — here are 30 reasons walking is the best exercise.

Click here to see states where Alzheimer’s causes the most deaths.
Click here to read our detailed methodology.