Troubled marriages can look good on the outside. In fact, many couples think that “getting along” is enough for happily ever after, but it’s not. Researchers at the University of Washington said couples who rarely argued were happy only in the beginning of their relationship, but three years later, the couples who fought the most had more stable marriages. That’s because they were able to work out their problems early on.

Marital studies say there’s a subtle difference between a good fight and a bad fight. It just depends whether it begins with a complaint or a criticism. A complaint is probably less combative. It sounds something like this: “I wish we could go on a date once a week.” However, a criticism launches into an attack on the person— Like this: “Why do you always have to zone out in front of the television on Friday nights? So much for date night.” Bad arguments aren’t the only red flags to look out for in a troubled marriage. Here’re three more, thanks to Healthwise magazine:

• A show of contempt: Rolling your eyes is harmful because of what it indicates: Contempt. It’s a sign you no longer value your partner.  The same researchers from the University of Washington said rolling your eyes also doesn’t give your partner an opportunity to respond, and is a clear indication your relationship might need outside help.
• Another thing that spots trouble in your marriage: The balance of power is off. That usually happens when social activities are controlled by one person. Dr. Howard Markman from the University of Denver says couples should plan activities they’ll both enjoy.
• The last thing that spots a troubled marriage: is staying in sync— or stagnant. In many marriages, “a lack of compatibility” seems to be the catch phrase couples use to express general discontent about the relationship. However, a study of 168 Pennsylvania couples revealed that those who eventually split were just as compatible in their leisure interests and their ideas about marriage as those who stayed together.