It’s no secret that keeping a happy marriage takes a lot of work. After the initial honeymoon phase, couples realize that they have to contend with each other’s mood swings and pet peeves for the rest of their lives. Throw in bills, kids, chores, and other obligations into the mix and you have two individuals who have to keep themselves from biting each other’s heads off.

But that’s not the entire equation. Married couples also have to deal with boredom. It’s that point where you’ve reached a plateau in your relationship and you begin to lose interest in each other. While it's normal for any relationship to go through some downtime, boredom is not something to be taken lightly. Judith Wallerstein, in her article for The Huffington Post, says that it can be the reason a marriage falls apart. So how do you liven things up between you and your spouse? Be on the lookout for these six warning signs.

(First published as "Keeping the Love Alive" in the "Marriage Matters" section of Good Housekeeping Philippines' May 2002 issue. Adapted for use in Female Network. Photo by Fedor Stroganov via Flickr Creative Commons. Additional reporting by Myra Mortega-Calulo.)