Dengue fever is a viral illness transmitted by the bite of infected Aedes mosquitoes, particularly Aedes aegypti. Symptoms typically include high fever, severe headaches, joint and muscle pain, rash, and mild bleeding. The disease is most common in tropical and subtropical regions, especially during the rainy season when mosquito populations thrive. There are four distinct serotypes of the dengue virus, which means a person can be infected multiple times. While most cases are mild, severe dengue can lead to serious complications, including hemorrhagic fever and shock, requiring immediate medical attention. Preventive measures focus on mosquito control and personal protection.