The dictionary describes heartache like this: heartache - intense sorrow caused by loss of a loved one.

I say heartache is waking up every morning knowing that he won't be there. It's knowing that when the phone rings,it won't be him on the line calling to see how you're doing. True heartache is not knowing when the emptiness and pain in your soul will go away.That's true heartache,and there is not a big enough Band-Aid to cover that wound.