A man is punched several times in the face and then brutally pistol whipped about six times by another man, knocking his teeth out. (Blood spurts out of his mouth and face with each increasing blow.)
A man tries to play the trumpet with no teeth causing blood to flow out of his mouth, down a trumpet, and all over himself and a bathtub. Fairly upsetting scene.
A man is found strung out on a carpet with a needle in his arm and blood covering his ear, mouth, neck, and part of his shirt; a woman finds him, wakes him up, and cleans him off with a washcloth and bowl of water. The bowl soon becomes bloody.
A uses heroin several times and struggles with his addiction. We see it once --although the sequence is an odd mixture of a flashback and biographical film-within-the film-- and other times it is implied or we see the aftermaths.
A man elbows a glass trophy case causing the glass to break.