I really don't have that much to say about love and, and why it hurts. When we feel heartache, for example, we are experiencing a blend of emotional stress and the stress induced sensations in our chest muscle tightness, increased heart rate, abnormal stomach activity and shortness of breath. Heartache is not the only way emotional and physical pain intersect in our brain.
Love itself does not hurt. It is growth that hurts. The ego that stings. Each transformation is painful because the old situation is being left behind for the new. For example, when a relationship ends we feel hurt, our hopes and dreams have crashed and we feel lost and lonely, wondering what comes next.