Work will consume as much time as we allow it. It will take over our whole lives if we let it. That's why striking a balance between our personal and professional lives is so difficult. We're waging an uphill battle against a crushing force called work.

Actually, the real conflict is within ourselves, according to Henry Cloud, a leadership consultant and clinical psychologist whose new book, The One Life Solution, addresses the work life balance issue.

Cloud notes that work life balance never used to be a problem because the personal and the professional were two separate spheres. But that's no longer the case. Our identities are increasingly tied up in our work. We take tremendous pride in our work. And in our effort to balance work and home, the two have become inexorably bound.

To prevent work from overcoming our lives, Cloud says, we need to have clear priorities. And we need to protect those priorities by establishing and adhering to rules that guide our conduct. In this boundary-less world, having our own personal boundaries keep us sane and focused on the things that matter most to us.

Cloud also maintains that we should understand the difference between things that are urgent (e.g. deadlines, e-mails, meetings, conference calls) and things that are truly vital, that revitalize us, such as our relationships with family, our hobbies and our spirituality. When we fail to distinguish the two, we repeatedly choose the urgent over the vital because, says Cloud, not attending to the urgent causes us immediate, palpable distress. The vital—the bike ride with our kids, the movie with a friend—can always be put off one more day. But when we put off the vital needs, we sacrifice relationships and, indeed, our own happiness.

Cloud spoke with CIO.com about the importance of taking control of our lives, setting priorities and creating boundaries. He also offers insight into the psychology of workaholics, the problems associated with living to work, and how to better manage our relationships with our BlackBerrys.

CIO: Fewer and fewer professionals seem to have a boundary between their work lives and their personal lives. Workers leave the office to attend parent-teacher conferences, for example; then they make up the time they were out of the office by doing work at home at night. Is there something wrong with this?

Dr. Cloud: It used to be that life and work were two different things. Work was a place, and when you weren't at the office, you were away from work and you had your personal life. There was also a time you went to work 8 to 5 and there was a time boundary. When you weren't at work, you were off. Those time and space boundaries contained work, and your personal life was a separate thing.

There are no more time and space boundaries separating people's work and personal lives. Pagers were the first to pierce that time and space boundary. They made it so your boss could find you anywhere, at any time. Then came the cell phone and the Internet and e-mail and PDAs.

Instead of thinking about these two separate lives, we have to think about how we get in control of what we're going to give our time to and what we're going to give our energy to. You absolutely have to be in control of that. If people don't have personal boundaries inside them at their core, they're going to feel fragmented and crazy and lost.

So the problem is trying to treat two things as separate that really aren't separate any more. Is it at all possible, in this day and age, to maintain some kind of separation between one's work life and one's personal life, or is that just a futile endeavor?

It has to be possible. If you think about it, we only have two things: We have our time and we have our energy. What you spend your time on and what you invest your energy in is what's going to grow.

I do a lot of consulting with high-level performers in some of the biggest companies in the world. And what I find over and over is that the higher their performance in their careers and the more fruitful their personal lives, the more they are in control of choosing where they're going to put their time and energy.