Dengue Hemorrhagic Fever (DHF) is a condition caused by the dengue virus, primarily impacting children under the age of 10. It is characterized by symptoms such as abdominal pain, bleeding, and sudden collapse. The illness begins suddenly with a persistent high fever and headache, accompanied by respiratory and gastrointestinal issues, including cough, nausea, vomiting, and stomach pain. Shock can develop between 2 to 6 days after the onset, leading to a sudden collapse, cold and clammy skin, a weak and rapid pulse, and a bluish tint around the mouth. Bleeding symptoms include easy bruising, skin spots, spitting up blood (hematemesis), blood in the stool, bleeding gums, and nosebleeds. Heart inflammation may also occur. The mortality rate is significant, ranging from 6% to 30%, with most fatalities occurring in children. Infants younger than one year are particularly vulnerable. DHF is also known as Philippine, Thai, or Southeast Asian fever.