The body is communicating with you at all times. Understanding your bodies communication mechanisms is an important skill that is usually underdeveloped. Most people are able to easily interpret basic signals such as thirst, hunger and fatigue. It is even fairly straight forward to understand that your body responds to the way you think, feel and act. When you are stressed, anxious or upset, your body reacts in a way that might tell you something isn't right. Butterflies in your stomach when you are nervous, flushed cheeks when you feel embarrassed are just a few examples of this phenomenon.
The mind and body are mirrors for each other and have an extraordinarily intimate two-way communication system.
Your body's physical health problems or symptoms (pain, illness, tension, etc.) can be an expression of what is going on in your unconscious mind and a reflection of how you are really feeling deep down. One of your bodies last resorts for getting your attention is to create pain and illness.