"Heavy" addresses the internal struggle against emotional oppression and the search for relief. Through the lyrics, the narrator expresses a sense of heaviness and anguish that weighs him down. They feel besieged and abandoned, fighting against negative thoughts and emotional pain.

Musically, "Heavy" stands out for its powerful chorus accompanied by lead guitars that add emotional emphasis with octave notes and slides along the neck. This technique, commonly used in genres like alternative rock, pop-punk, and metalcore, showcases the versatility and skill of guitarists Héctor Fernández and Garrison Frey throughout their career.