It's difficult not to discuss personal details of your life with the co-workers you spend at least 50 per cent of your waking hours with. Some of us spend more time at work than we do at home and it would be maddening to not be able to enjoy a certain degree of interpersonal exchange while on the clock.

But there is such thing as sharing too much information -- or TMI. When co-workers chit-chat freely about private matters such as marital problems, weekend drinking binges or intimate medical procedures, it can be awkward for the listener and a potential career torpedo for the speaker.

While sharing a little personal information helps build good working relationships, once you cross the boundary into TMI, you are erasing the line between the "work" you and the "real" you. That can sometimes affect your professional reputation (there goes the promotion!), the respect you've earned and the trust people have placed in you.

Here are examples of TMI -- details you really should avoid "oversharing" at work:

1. Medical history. There is a reason why hospital and human resources departments are not allowed to divulge your confidential health information, because people may treat you differently if they knew you suffered from a medical condition. Do your co-workers really need to know about the skin cream your doctor just prescribed?

2. Divorce proceedings. Fine if you think people need to be aware that you are going through a life-altering event, especially if you need to occasionally be away from work because of it. But refrain from giving blow-by-blow accounts about a nasty legal battle or ongoing "he said/she said" bickering with your ex.

3. Salary information. It's never a good idea to tell others how much money you make; it only causes jealousy and competitiveness. Likewise, if you rave too much about making extravagant purchases and leading a lavish, privileged lifestyle, it usually only makes people wonder why you deserve it.

4. Credit history. Complaining about how much monthly interest you pay to your creditors, how much debt you're carrying or your poor spending habits is not productive workplace conversation. It can also lead some to question your ability to manage work-related projects that include financial dealings.

5. The therapist's couch. It's great that you've decided to see a counsellor or therapist, but your sessions should remain private unless you want to be the fodder for gossip. Also, refrain from trying to apply psychology 101 to solve your colleague's problems. No one asked for your diagnosis.

6. Relationship highs and woes. Matters of the heart are always better left out of the workplace, especially if your love life has more drama than an episode of The Young & The Restless. It's probably not all that interesting to anyone as much as it is to you.

7. Your plans to quit. Even if you are job hunting during work hours, don't tell your co-workers about it. It's amazing how fast news travels directly to the boss's office.

8. Political leanings and religious beliefs. These hot-button topics can quickly escalate into out-of-hand discussions in the lunch room, which can set off divisiveness. With the daily newspaper open or the TV switched on, it may be tempting to express your opinion without remembering that not everyone will agree with you.

9. The latest, cutest, most wonderful or terrible thing your child or pet has done. For people without children or pets, even the most endearing stories recounted again and again get to be tiresome. For professional reasons, it's also not a great idea to get branded at work as The Cat Lady or Mr. Mom.

10. Gossip. Sometimes loose lips really do sink ships. Don't spread rumours about others' personal lives and don't reveal information about yourself that can be turned into gossip for others to dine on.

Remember that the workplace can also be highly competitive. Whether you think you might be sharing a secret with a confidante or delighting your buddies with a humorous anecdote from the weekend, never offer TMI that could be used against you by someone eager to further their career at your expense.

You are the only one who can choose what and how much information you want your co-workers to know about you. So keep it in check. If you don't want to hear it repeated at coffee break, don't mention it around the water cooler in the first place.

-- With reporting by Barbara Chabai

John McFerran, PhD, CMC, F. CHRP, is founder and president of People First HR Services Ltd. For more information, visit www.peoplefirsthr.com.

RESEARCH:

http://www.cnn.com/2009/LIVING/worklife/02/16/cb.tmi.at.the.office/?iref=mpstoryview

http://www.theglobeandmail.com/servlet/story/RTGAM.20090223.wlinfo23/BNStory/lifeWork/home

http://careerplanning.about.com/cs/personalissues/a/personal_info.htm