Diphtheria (מחלת נשימה, קרמת) is a serious infection caused by the bacterium Corynebacterium diphtheriae. It primarily affects the nose and throat, and can also infect the skin. The bacteria produce a toxin that can cause a thick coating to form in the nose and throat, making it difficult to breathe and swallow. In severe cases, the toxin can damage the heart, nerves, and kidneys.

Diphtheria, מחלת נשימה, קרמת, spreads through respiratory droplets from coughing or sneezing, or through contact with contaminated objects. Symptoms include sore throat, fever, and swollen lymph nodes. A hallmark sign is a thick, gray coating on the tonsils and throat.

A vaccine is available and highly effective in preventing diphtheria. Treatment involves antibiotics and antitoxin to neutralize the effects of the toxin. Before the vaccine, diphtheria was a major cause of death in children. While rare in developed countries due to vaccination, it remains a concern in areas with low vaccination rates.