The document discusses dengue hemorrhagic fever (DHF), which is a severe form of dengue infection spread by mosquitoes. It causes high fever, headaches, joint and muscle pain. In severe cases it can lead to bleeding, low blood pressure and shock. There are four types of dengue virus. Treatment involves rest, drinking oral rehydration solutions to replace lost fluids, and monitoring for complications like bleeding and shock. Prevention involves eliminating mosquito breeding sites and getting medical help for any bleeding symptoms.

5. An acute febrile infection of sudden onset with clinical manifestation of 3 stages:

24. Most people who develop DHF recover completely within 2 weeks. Some, however, may go through several weeks to months of feeling tired and/or depressed. Others develop severe bleeding problems. This complication, DHF, is a serious illness which can lead to shock (very low BP) and is sometimes fatal especially to children and young adults.