Communication is related to health due to understanding and misunderstandings, as well as achieving/finishing and completing tasks for others and yourself. If you are given scarce information than the info received will be unhelpful and unfulfilling, this making the task impossible to finish, such as the brain processes stress, anxiety, frustration to not being able to complete said task imposes that stress onto your body which is not good for its health. Stress, Anxiety, Frustration, Anger, Sadness basic and intricate emotions brought to this level so highly is not only bad for your body and heart but can later on impose serious health risks and mental risks that further increase said problem.
There is also taking on the idea of not being able to understand someone can make things nearly impossible to maybe receive something you need to live, say you land somewhere that the only way you can get food is through a secret password that is in a completely different language you cannot understand! :( Well your body is going to quickly die of starvation and stress of trying to get that food that just speeds that process up. In everyday life too, you need money to buy said food, otherwise you have to ask/borrow/steal or dig for food elsewhere. You need communication to help with keeping your body healthy and also allowing a vent of communication to others. You need it to receive and finish tasks and obtain needed items/foods/medicine etc.
Going into more psychology- Communication is very effective to behavior and decisions, you learn from those around you and because of this your ideas, ideals and opinions are often very well opinionated and influenced. Your behavior is based on what others around you also do. Reactions to mistakes, the reaction to losing something, the reaction to someone hitting you, these are not only natural reactions of anticipation and savage human nature but also of influence to what you see around you. You may choose to hold a bigger reaction in because society tells you its embarrassing to over react. Your decisions is because of that observation due to communication around others; People say its bad, you see others follow, your reaction follows in suit. You avoid embarrassment related to stress or anxiety that could further effect your health negatively.
That's the complete full cycle.
Hopefully that helps.
