Binding of Isaac: Rebirth Wiki

Added in Repentance

Hemoptysis is an unlockable passive item added in The Binding of Isaac: Repentance.


  • Double-tapping a fire button causes Isaac to sneeze blood, dealing damage to enemies in front of him. The sneeze deals damage equal to 1.5x Isaac's damage, knocking enemies and projectiles back. Enemies knocked back take 10 damage when hitting a wall or obstacle and deal 10 damage to other enemies they hit.
    • The sneeze has a cooldown of 1 second.
  • The sneeze applies a curse to enemies. Enemies under the curse will take more damage from Brimstone Brimstone-like laser attacks and violently explode on dying to these attacks, damaging and spreading the curse to nearby enemies. Any enemies spawned by those under the curse will also be cursed.


  • Tainted Azazel Tainted Azazel begins with an inherent version of Hemoptysis that allows him to deal full damage to cursed enemies.
  • The sneeze's range is affected by the shot speed stat, and not by the range stat itself.
  • The sneeze can push Bomb Bombs, pickups and enemy shots.
  • The collision damage can be used to damage Host Hosts while their skulls are lowered.



  • Ipecac Ipecac: The sneeze causes an explosion. The explosion deals additional damage equal to 3x Isaac's damage +10 and will not hurt Isaac.
  • Tainted Azazel Tainted Azazel: The innate sneeze ability is entirely separate from Hemoptysis, and so the sneeze can be triggered twice in quick succession. However, triggering the sneeze from Hemoptysis will cancel Tainted Azazel's brimstone charge, meaning that this item is largely ineffective as this character.

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  • Hemoptysis is the medical term for coughing up blood.