Well if you are in an unhealthy relationship obviously you won't be mentally stable because unhealthy relationships generally involve name calling and rue remarks, and sometimes physical abuse, which would affect your phycial wellbeing aswell.
On the other hand, if you are in a healthy relationship, your health triange would be postivly affected because this person makes you happy if you consider it to be a healthy relationship.
Hope this helps! Have a nice day :)
- Uni
