The unspoken rules in a dysfunctional home. To feel is to be weak and a crybaby. To speak is to be a snitch or disloyal. To trust is to be naive and leave yourself vulnerable (which is also weak). 

As an outsider looking in, these are invisible traits and hard to spot. It might be a two parent family with a straight A child, six figure income, and smiles every time you meet them. It can also be a family of six with a single mom on welfare trying to make the best of things. A dysfunctional family comes in all shapes, sizes, colors, and socioeconomic backgrounds. Sometimes alcohol and drugs play a part, other times they do not.
If you come from a dysfunctional family and want to break the cycle, you MUST break the rules. Experience the full range of emotions, even the painful ones. Talk about your thoughts/feelings. And find people in your life you can trust. Previously I have talked about healthy boundaries. A good boundary is knowing when to trust and let someone know the real you.
Distance yourself from toxic relationships. Sadly, these may be close family members. Distancing can mean physically or emotionally. If someone is a physically and emotionally abuse spouse, yes get away, far far away. If the toxic person is parent or sibling and you do not want to be physically separated, you can put up emotional walls that decrease the effect their words have on you.
I have a friend whose mother would constantly belittle and demean him. He did not speak to her for many years. When his mother fell ill he felt obligated to care for her, but was nervous about seeing her. He was older and more able to handle the emotion abuse but was tired of hearing it. He developed an internal coping skill, knowing he did not deserve to be disrespected. When his mother began a rant, he started looking around at his environment describing the objects or people in his mind. Sometimes he was able to just tune out and not hear her. Realizing he no longer listened to her at all, his mother decreased her negative rhetoric. By distancing himself emotionally he was able to care for his mother with a closer relationship than ever and she passed peacefully in her home a few years later.
When you are ready, break the rules of dysfunction and break the cycle.