'Heartache' more often than not refers to a state of emotional or psychological distress, primarily due to reasons related to one's love life. So often, we hear people complaining of heartache when their beloved doesn't reciprocate their love enough or when they part from someone they are truly in love with. They feel let down and overwhelmed with solitude. This pessimistic display of emotions can be put as heartache.
Heartache is seldom referred to physical pain; instead it is characterized by feelings such as anguish, disappointment, obsession and longing for someone amongst many others. It is more of a horrible pain signifying a huge emotional void in a person's life. Well, just like many other emotions, heartache too is temporary. People do recover from heartaches, come out their self imposed social exiles and transform themselves into better individuals. Life is all about taking things in your stride and having a positive outlook. So the next time you see someone complaining of heartache around you, counsel them out of it.