Dengue symptoms typically appear 4–10 days after infection and can include high fever, severe headache, pain behind the eyes, muscle and joint pain, nausea, vomiting, rash, and fatigue. Severe dengue, also known as Dengue Haemorrhagic Fever, can cause warning signs such as severe abdominal pain, persistent vomiting, bleeding from the nose or gums, blood in stools or vomit, rapid breathing, and extreme weakness. If these symptoms appear, seek immediate medical attention.