If he's moving a long distance to live with you, he's leaving his social network and friends. Most caregivers drastically underestimate how hard it is and how long it takes for someone to adjust to a new environment in a new town. "It's huge," says Schempp. "How are you going to deal with their loneliness issues? They're going to look to you for their socialization. How are you going to either integrate them into your life or help them create a new life for themselves?"

If you and your spouse are at work and the kids are at school, that could mean a lot of alone time for your older relative. Rather than have him just sit around and watch TV all day, you'll want to find out whether there's a senior center or adult daycare facility nearby. Does he drive or will you or another family member have to provide transportation? Is he healthy enough to use public transportation?

Are adult daycare facilities available near you? They offer personal care such as exercise and even transportation, and provide cultural activities such as art or photography classes or trips to museums. Likewise, senior centers can provide a great social network and generally are free or have very low annual membership fees.