When a marriage is in decline, it tends to follow a predictable pattern. Knowing what to look for can help you repair your relationship before its too late.

Becky Whetstone , an Arkansas marriage and family therapist and the author of the forthcoming book I (Think) I Want Out, has spent more than 20 years counseling couples. She wrote her Ph.D. dissertation at St. Marys University in San Antonio on the stages of a deteriorating marriage.

This is the most important thing couples could know, Whetstone told HuffPost via email. [Its] similar to understanding cancer symptoms, the stages of cancer and early detection.

While doing research for her dissertation, she came across the work of sociologist Diane Vaughan , the author of Uncoupling: Turning Points in Intimate Relationships. In her 1986 book, Vaughan delineated the various stages, or turning points, that individuals go through when ending a relationship. After interviewing more than 100 people about their breakups, Vaughan discovered that most splits followed a very similar trajectory.

When I read it, I was like, Oh my gosh, why dont people know about this? Whetstone said.

Then, Whetstone conducted her own in-depth interviews with a set of subjects, hoping to find some common patterns in the dissolution of their relationships, she said.

When I did my own research, interviewing 11 subjects for two hours apiece and asking them all the same exact questions, I wasnt thinking about Vaughans stages at all, she said. I was looking for common patterns in what my subjects told me and was open to anything. But, lo and behold, Vaughans stages revealed themselves.

These stages are mostly experienced internally, occurring in the mind of the decider (the individual whos initiating the breakup), Whetstone explained. Often, this person doesnt voice their relationship concerns to their partner until late in the process.

Unfortunately, unhappy partners keep the extent of what is going on a secret from their spouse until it is almost too late, Whetstone said. Its so important that partners stay in touch and let the other know when they are struggling.

Below are five stages of a dying marriage outlined by Whetstone. The first four align with some of Vaughans findings, while the fifth is one that Whetstone discovered in her own research, she said.

Stage 1: Disillusionment

The first stage, known as the disillusionment phase, is when one person recognizes that theyre unhappy in their relationship, but they decide to take a wait-and-see approach.

They mull it over and say, You know, relationships have ups and downs, and Ill just see how this goes and see if my feelings change, Whetstone said.

But as Vaughan told The Washington Post in a 1986 interview: When you keep secrets that have to do with the relationship things that make you unhappy, things that can be fixed a breach is begun. ... It widens the gap.

Stage 2: Erosion

The second stage is the erosion phase. This is when one partner realizes that the unhappiness is not just going away and is serious enough that it could lead to divorce. Still, they dismiss the idea of splitting up for a number of reasons because of kids, finances, reputation, religion, values or whatever it is they dont want to lose, Whetstone said.

The cracks begin to show, she said. They may make sarcastic remarks to their spouse, complain, get an attitude, or roll their eyes, but whatever it is, it stays between them.

In other words, this person might make snide comments toward their spouse, but only behind closed doors not in front of other people, Whetstone noted.

Stage 3: Detachment

The third stage is known as the detachment phase, in which a person pulls away from their partner emotionally and looks for things outside of the marriage to help them cope. That might mean investing time in a hobby, a workout regimen or even having an affair, Whetstone said. But this person is still not willing to end the relationship.

So, they make a deal with themself: I can stay married if I find something outside the marriage and away from my partner that brings me satisfaction, Whetstone explained.

They are focusing more and more on their unhappiness, seeing every little negative thing and becoming more blind to the things they once enjoyed.

By this stage, the hostility starts to become apparent to folks outside of the relationship.

The poisonous feelings seep out in front of others, said Whetstone.

Stage 4: The Straw

At this point, a persons tolerance for their partner continues to dwindle and the marriage moves into the fourth stage, known as The Straw. Whetstone described it as a day when their spouse says or does something that gives them sudden clarity that they cant be married to someone who would do that thing.

At this moment, they emotionally unplug, turn their back on the marriage and refuse to cooperate or go along, pretending they are happy, she explained.

The straw that breaks the camels back might be something thats big, small or seemingly innocent, Whetstone said. But for the disgruntled spouse, everything has changed.

They will either decide to end the relationship altogether, make a pronouncement of their thinking they want a divorce or emotionally disconnect, Whetstone said.

Stage 5: Death Of The Marriage

In Whetstones research, she uncovered a fifth stage, which she refers to as death of the marriage.

Or at least death of what has been going on before, as the spouse will not go back to the way things were, she said.

At this point, divorce is likely, she said, but it is possible that a future with their partner can be found under the right circumstances.

The status quo, however, is forever off the table, she added.

How And When To Salvage The Relationship

Whetstone advises couples to start counseling when they hit the erosion stage the point when they recognize there are issues that wont resolve on their own.

Letting the resentment pile up makes it exceedingly difficult to help them later, she said.

What gets in the way of early intervention? Too many people mistakenly believe that couples therapy is reserved for really bad, damaged marriages, Whetstone said, when thats just not true. Small issues can snowball into much bigger and trickier ones if ignored.

Northern California therapist Kurt Smith , who specializes in counseling men, said that when it comes to starting couples therapy, the sooner, the better.

Sadly, most wait until its almost too late, and for some it is, he told HuffPost. Often they finally go when theyre close to calling a divorce lawyer or already have.

Thats why Smith recommends seeking counseling proactively rather than reactively.

As soon as you start seeing signs of a potential problem you cant fix yourselves, go, he said. At this stage its much quicker, cheaper and has much better results.

The adage time fixes everything doesnt apply to marriages on the rocks, Smith said.

Lets just give it some time is an avoidance, and sometimes a power play, he continued. Dont accept it. In addition to time, you also have to add strategies and effort to the mix to bring about real change, especially change that lasts. Be smart and be willing to admit when you cant fix it yourself.

What if your partner wont go to marriage counseling? Then go without them, Smith said.

Marriages can change even if only one person is trying, he said. Ultimately, do you need both partners participating? Sure. But you can get started without them. And often when you do, theyll join you at some point.