You deserve happiness, and if living year after year in a miserable long-term marriage stands in the way of your happiness, it might be time to call it quits. It is unfair and unnecessary to give your life over to somebody who no longer appreciates you. Worse, if you live in a marriage that is beyond repair, it can literally make you sick. A WebMD.com article titled "Is Your Marriage Toxic?" warns of the negative physical effects of a stress-filled relationship, especially when it has been a long-term one.

David Woodsfellow, Ph.D., a Georgia marriage counselor, explains in a "CNN: Living" article that long-term marriages generally do not end abruptly. A couple may start out happy but at some point, that joy begins slipping away. Day after day and year after year, the two of you slowly drift apart. The process is often slow and insidious. If you look at your relationship and the only thing left is a vow that long ago lost its meaning, it might be time to leave. Infidelity is an exception and can kill any marriage fast, even mature ones.

If there is no relationship -- sexual or appreciative -- your marriage has likely reached its point of no return, says marriage expert Larry Bilotta. Perhaps every discussion evolves into an argument and one or both of you focus on a history of past negative events. You may not find the other attractive, at all, or maybe you do not enjoy one another's company. Your goals and values may be totally different. A sure sign that you should probably call it quits: Feelings for one another may have become so lost that you might as well be on another planet.

Sometimes, it is completely appropriate to leave a marriage immediately. Some women have endured emotional and verbal battering for decades. When it escalates into physical abuse, though, things have gone too far. Other times, a spouse undergoes a sudden personality change, sometimes due to substance abuse, and becomes violent and impossible to live with. In these cases, it is imperative to protect your safety and leave. Most communities have an agency that assists women caught in these situations, and the local United Way maintains a directory of helpful services.

There are many reasons a couple stays together in a broken marriage. The mere fact of having been together so long is reason enough for some. Others are afraid of hurting their children, while some are simply stuck economically or emotionally. A married couple may remain together out of a sense of obligation, duty or gratitude. Long-term relationships, even bad ones, form a powerful adhesive that is almost impossible to break. To break up, one of you will have to leave your home, and that's never easy. The fear of being alone is too much for some to bear.