Heartsick means feeling deeply sad or emotionally hurt, the kind of sadness that feels almost physical, like an actual ache in your chest. When you're heartsick, you're genuinely suffering from emotional pain that goes beyond ordinary disappointment.

You might feel heartsick after a best friend moves away to another state, or when a beloved pet dies. A character in a story might be heartsick with longing for their home after years away. The word captures that heavy, hollow feeling when something you care about deeply has gone wrong or been lost.

The “heart” part shows how emotional pain can feel surprisingly real in your body. The “sick” part reminds us that intense sadness can drain your energy and make everything feel harder, almost like having the flu. When someone is heartsick, they're experiencing genuine suffering that affects how they feel physically and emotionally. It's a word that acknowledges that emotional wounds can hurt just as much as physical ones, even though you can't see them or put a bandage on them.