Diphtheria is a life-threatening infection that spreads easily. It is caused by bacteria. The infection most commonly attacks the tonsils, throat, and nose.

Diphtheria is a medical emergency that requires immediate care from your doctor. Not everyone who gets diphtheria shows signs of illness, though they may be able to infect others. The sooner it is treated, the better the outcome will be.

Diphtheria is caused by the bacteria Corynebacterium diphtheriae. The infection spreads from person to person through contact with:

  • Droplets of moisture that are coughed or sneezed into the air by an infected person and breathed in by a non-infected person
  • Personal items, such as tissues or drinking glasses, that have been used by an infected person
  • Skin that is infected with diphtheria