An unhappy marriage is defined when one or both people feel negative feelings towards each other like bitterness and resentment.

A person would have frequent fights with their spouse and experience feelings of despair regarding their marriage. Staying in an unhappy marriage can effect one both mental and physical health of a person.

The following are the impacts of being in an unhappy marriage

Increased level of stress

Self esteem goes down

Increased conflict 

Finding happiness elsewhere is less

Negative effects will be reflected on children

Tips for handling an unhappy marriage

When a person chooses to day in an unhappy marriage, there could be many things that they can do about it and try to make it work or reduce the conflict.

Focus on the positives

Discuss about it openly and honestly

Keep a commitment

Know when to move on

Source: https://www.medicalnewstoday.com/articles/consequences-of-staying-in-an-unhappy-marriage#seeking-professional-help