A relationship should nurture and support those involved. However, sometimes a relationship can have negative influences on one or both partners.
2 people involved in a relationship
Features of a toxic relationship:
(1) The relationship is damaging to the mental, psychological or physical state of a person.
(2) The toxicity may affect one or both the people in the relationship.
(3) The negative influence tends to reverse when the people are apart.
A toxic relationship may involve abuse.
A person with co-dependency issues may be more vulnerable.
A narcissist or sociopath may be more likely to have toxic relationships.