When a family member experiences a problem, it effects the entire family. The same holds true that when the family unit experiences a crisis or is dealing with a difficult issue it effects individual members within the family. Each members' interactions effect the family as a whole in positive and negative ways.
Healthier functioning of the family can occur by helping family members recognize and change ineffective patterns of interacting with one another, as well as finding solutions to problems.
This is known as the Systems Approach to Family Therapy.