Judging by the imagery, this is a poem about a child living with an alcoholic, violent parent. The speaker describes a bottle breaking, the smell of bourbon, and a fist swinging, and the short, clipped lines make it feel like the blows landing one after another. The "water" that runs red is blood, and the sweat stinging the sores suggests the speaker is both frightened and hurt. Nothing in the poem tells us exactly who the speaker is, but the boy who "screams" at only fifteen may be the speaker or someone close to them.
The mood is tense, bleak and claustrophobic. The speaker feels trapped, powerless and worn down: "I'm the one to lose." The closing line twists the saying "blood is thicker than water." Here it seems to mean that family ties don't protect anyone. They are the very thing that holds the boy in place, cowering, while the violence goes on.