What is the most common injury or sickness caused by diphtheria?

The most common injury or symptom of diphtheria is a thick, gray membrane that covers the back of the throat and tonsils. This membrane can obstruct the airway, leading to difficulty breathing and potentially life-threatening complications. Other symptoms may include fever, sore throat, hoarseness, swollen glands, and difficulty swallowing. In severe cases, diphtheria can also cause damage to the heart, kidneys, and nervous system, leading to serious complications and potentially death.