Diphtheria is a serious bacterial infection caused by the bacterium Corynebacterium diphtheriae. It primarily affects the throat and nose, leading to symptoms such as a sore throat, fever, and a thick gray or white coating in the throat. If left untreated, it can cause severe complications, including difficulty breathing and heart problems. The disease spreads through respiratory droplets when an infected person coughs or sneezes. Vaccination is the most effective way to prevent diphtheria, and the DTaP vaccine is commonly given to children. Early diagnosis and treatment with antibiotics are crucial for recovery.