Dengue fever is a contagion- caused complaint that is spread by mosquitoes. Dengue is an acute viral illness caused by RNA contagion of the family Flaviviridae and spread by Aedes mosquitoes. A womanish Aedes aegypti mosquito carrying a blood- mess from a mortal host through her honker which penetrates the host’s skin. That occurs in tropical and tropical areas of the world. The complaint is now endemic in farther than 100 countries in the WHO Regions, analogous as the Americas, Africa, the Middle East, Asia, and the Pacific islands & also other countries who can suffered these world wide spread complaint. About half of the world’s population is now at trouble of dengue with an estimated 100 – 400 million infections being each time. The severe form of dengue fever, also called dengue hemorrhagic fever, can beget serious bleeding, a unlooked-for drop in blood pressure (shock) and death. Symptoms include high fever, severe headache, joint and muscle pain, nausea, and puking. Treatment for dengue fever includes supportive care, analogous as rest and fluids. The complex pathogenesis of thrombocytopenia and increased vascular permeability in dengue illness is also mooted. The composition give a detailed overview on dengue contagion infection, medium, symptoms, discriminative opinion & prevention & treatment.