UnitedHealth Group (NYSE:UNH) reported earnings today, beating on the top and bottom lines. Excellent.

But let's dig a little deeper, to the business behind the numbers. The key question for investors to ask is whether UnitedHealth Group is fundamentally healthy under the positive top-and-bottom line news.

In the video below, Motley Fool health care analysts Michael Douglass and David Williamson lay out three key takeaways from UNH's second quarter earnings.