The most widely-accepted theory of how relationships develop was created by Mark Knapp, a professor at the University of Texas who co-wrote the book "Interpersonal Communication and Human Relationships." The five stages of relationship escalation are initiating, experimenting, intensifying, integrating and bonding. Knapp also created a five-stage model to describe how relationships wither and eventually end. This five-stage model of relationship termination begins after the couple has already gone through the first five stages.

The Differentiating Stage

If you and your partner have been together for a while, then one or both of you might start to feel the need for a little space. When the relationship was newer you did everything together because you wanted to do everything together, even to extent of spending less time with your friends and paying less attention to your favorite hobbies. After some time has passed, you start making more time for your friends and hobbies again or even develop new interests and make new personal connections. This is the differentiating stage, and it doesn't necessarily have to lead to a breakup if you continue to prioritize your relationship. Couples in this stage typically argue more often than before, followed by apologies and attempts at compromise, according to researchers Theodore Avtgis, Daniel West and Tracy Anderson in the article, "Relationship Stages" in "Communication Research Reports."

The Circumscribing Stage

If you start to feel that you and your partner are drifting apart, you may have entered the circumscribing stage. In this stage, the two of you talk less often and with less depth. When you have a disagreement, you don't risk an argument by talking it out. Instead you just withdraw from the conversation and go spend time by yourself or with friends. Knapp considered this the last stage at which the relationship could still be saved by talking about how to get back on track. Couples in this stage feel anxious around each other and start to act cold or distant, according to Avtgis et al.

The Stagnating Stage

If you avoid saying anything about the things that matter to you because you already know what your partner will say, you may have entered the stagnating stage. This is the stage when other people around you start to realize that your relationship is having problems. From this point on, the relationship is in serious trouble and can only be saved by a major effort. According to Avtgis et al, couples in the stagnating stage may stop being affectionate with each other or going out places as a couple. If you are in this stage, you may no longer enjoy your partner's company and both of you might feel that you are just going through the motions without any real feeling.

The Avoiding Stage

The stagnating stage is painful and unhappy for both people. To avoid the awkward, tense interactions you've been having, you may begin to avoid each other. If you find yourself making other plans or taking on extra hours at work just to avoid spending time with your partner, you may have entered the avoiding stage. At this stage the relationship is almost over, but the stage can drag on for a while until one of you decides to officially end it. Couples going through this stage stop communicating with each other, states Avtgis et al.

The Terminating Stage

The terminating stage begins when one partner announces the desire or intention to break up. It often involves a conversation about what went wrong, but it can sometimes happen suddenly with no conversation. Sometimes one partner just stops calling or moves away. The terminating stage can be very painful but doesn't always have to be. Some couples realize they aren't right for each other romantically but have no hard feelings and may even remain friends. Some people actually feel happier -- or, at least relieved -- when they reach this stage.