Skip directly to search Skip directly to A to Z list Skip directly to navigation Skip directly to page options Skip directly to site content


Photo of child with swollen neck due to diphtheria infection

A child with swollen neck due to diphtheria infection.

When the bacteria that cause diphtheria invade the respiratory system, they produce a poison (toxin) that can cause:

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

Within two to three days, a thick coating can build up in the throat or nose, making it very hard to breathe and swallow. This thick gray coating is called a "pseudomembrane" and it can build up over the nasal tissues, tonsils, voice box, and throat.

The pseudomembrane is formed from dead tissue caused by the toxin that is produced by the bacteria. The pseudomembrane sticks to the tissue below and may get in the way of breathing. The toxin may be absorbed into the blood stream and may cause damage to the heart, kidneys and nerves.

 Top of Page

Related Pages

  • Diphtheria for Parents: The Basics
    Describes symptoms of infection as well as benefits and risks of vaccination.
    English [2 pages]   |   Spanish [2 pages]
  • Diphtheria for Parents: In Depth
    Offers information about recent diphtheria outbreaks. Describes symptoms of infection, benefits and risks of vaccination, details about the vaccine, and history of the disease.
    English [2 pages]