Measles is a highly contagious viral infection caused by the measles virus, spreading through respiratory droplets. It begins with fever, cough, runny nose, and conjunctivitis, followed by Koplik’s spots in the mouth and a red, blotchy rash that spreads from the face downward. While common complications include ear infections and diarrhea, severe cases can lead to pneumonia, encephalitis, or even death. There is no specific antiviral treatment, but supportive care helps manage symptoms. The MMR vaccine is the most effective prevention method, significantly reducing measles-related illness and fatalities.