As the executive coaching industry has grown, so have concerns that some don't have the credentials or experience needed to truly help their clients. Here are a few things to consider before hiring one.

By Katherine Reynolds Lewis

FORTUNE -- When William Cui first became a management consultant, he was ready to sell his home in Delaware and put all his belongings in storage. No use owning property when he'd be traveling all over the world for the foreseeable future, right?

But his career coach stopped him from packing everything away. "She said, 'You need to have somewhere to call home to tie you back to who you are,' " recalls Cui, who is now 33 and a senior manager in Cognizant's business consulting practice. "When you're traveling and living an interesting life that most people would be jealous of -- you're living in fancy hotels, traveling around the world, and doing exciting things -- a lot of us end up losing ourselves."

Cui says he has remained grounded by having a home where he could unpack his suitcase and make a bowl of noodles for dinner, even just for an overnight between trips. And his career coach has helped him with much bigger issues as well, most notably when he was weighing job offers from consulting firms McKinsey & Co. and Booz & Co. With her coaching, he realized the mentoring at Booz rather than the sink-or-swim McKinsey model would help him more in the long-run.

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Cui is hardly alone in relying on a coach for general career advice, as distinct from help with job hunting. A survey by the International Coaching Federation found that there were 47,500 professional coaches worldwide this year, up from 30,000 just five years ago. And nearly 60% of coaches surveyed said they'd experienced an increase in clients during the previous year.

But as the industry has grown, so have concerns that some coaches don't have the credentials or experience needed to truly help their clients, given that the profession isn't regulated in the way that psychology, social work, or even accounting are. Career coaching may not be quite as prone to hucksters as life coaching is, but there's still the potential for exploitation, harm, or simply a waste of time and money. More