Photo of child with swollen neck due to diphtheria infection

A child with swollen neck due to diphtheria infection.

Bacteria that cause diphtheria can get into and attach to the lining of the respiratory system, which includes parts of the body that help you breathe. When this happens, the bacteria can produce a poison (toxin) that can cause:

  • Weakness
  • Sore throat
  • Fever
  • Swollen glands in the neck

The poison destroys healthy tissues in the respiratory system. Within two to three days, the dead tissue forms a thick, gray coating that can build up in the throat or nose. Medical experts call this thick gray coating a “pseudomembrane.” It can cover tissues in the nose, tonsils, voice box, and throat, making it very hard to breathe and swallow.

The poison may also get into the blood stream and cause damage to the heart, nerves, and kidneys.

Page last reviewed: December 17, 2018