Q. Is it true that heart failure can cause dementia and/or Alzheimer disease?

A. Heart failure in elderly people has indeed been linked with dementia problems, including Alzheimer disease. Of course, both conditions are frequently seen in this age group, but research in people age 75 and older indicates that heart failure does raise the risk of dementia in older adults.

In heart failure, the heart doesn’t pump blood well. As a result, blood and other fluids collect in body tissue, congesting the blood vessels and lungs. According to research, the connection between heart failure and dementia may well be explained by the fact that the brain is not getting enough oxygen-rich blood due to poor circulation, particularly in very old people.

A recent study suggests that in people with heart failure, the risk for dementia may be reduced by drugs that lower blood pressure—particularly diuretics, or “water pills,” which help the body eliminate excess water and sodium, relieving the congestion caused by heart failure. However, more work is needed to confirm that finding.

Questions are selected that reflect the wide variety of health problems of general interest. We cannot, however, respond specifically to the personal health concerns of an individual.