Trust is a big part of a healthy relationship because when you have trust there's no doubting or second guessing or questioning. When trust is there a healthy relationship is there!
When there's communication there's cooperation and a efficient way of talking without a argument or something happen. Communication is how we should all talk with care and understanding. When there's communication there's a healthy relationship!
Respect is huge. When there's respect there's empathy, understanding and trust. Respect bridges all the gaps and is the most important thing to a healthy relationship in my opinion. When there's respect there's a healthy relationship!