They say that indoor air can be significantly more polluted than outdoor air, especially in newer homes where windows and doors are tightly sealed. Using a HEPA filter can reduce indoor air pollution by removing small particles from the air, like dust, mold, and pet dander.

But recent research also suggests that using a HEPA filter may also improve heart health. Non-smoking elderly participants ran HEPA filters in their homes for 48 hours, and doing so improved the function of small blood vessels. There are small blood vessels that also feed the heart.

When I bought filters for two of the bedrooms in our home, I didn't realize until months later when I went to change the filters that I'd bought "HEPA-like" filters. These do not remove the very fine particles in the air like cat dander so, if you're going to buy a HEPA filter, make sure you read the packaging carefully!