Have you given much thought to the "personal" side of retirement? You may have created a retirement income strategy and addressed your estate-planning needs, but social interaction in retirement is something to plan for too. And it's just as important.

As human beings, we are hardwired for social connection. Maintaining that connection as you age gets harder, especially since you may lose a large portion of your social network when you retire. Enter the possible downside of retirement: social isolation. The social isolation that some feel in retirement can be linked to several serious health conditions, including heart disease and dementia, according to a recent National Institute on Aging report. It also simply makes for an unfulfilling retirement.

Fortunately, you can do a lot to strengthen your existing social connections and build new ones once you've retired. Here are 4 tips for staying connected:

Volunteer. Many retirees get a great deal of satisfaction from volunteering. In fact, 87% of retirees say that being useful helps them to feel youthful, according to the Four Pillars study. And since you have decades of valuable experience, you likely have a lot to offer many volunteer groups.

Take a class. Have an interest in cooking, gardening, boating or something similar? Consider taking a class. You'll connect with people who are interested in that as well AND learn more about something you enjoy.

Join a social club. Like taking a class, you can find a social club for almost any of your interests – books, movies, sports, hiking, ballroom dance and so on. Look on social media or by a simple internet search in your area to find a club to join.

Schedule time with family and friends. Nurturing your relationship with family and friends is important too. Take the initiative to schedule regular activities, like lunches or walks, with friends and family. You could even invite them to try any of the above with you.

When you’re retired, your time is your own – and you’ll enjoy this time much more by staying socially connected to the individuals and communities in your life.