Dengue should be suspected when a high fever (40°C/104°F) is accompanied by two of the following symptoms: severe headache, pain behind the eyes, muscle and joint pains, nausea, vomiting, swollen glands or rash.
Symptoms usually last for two to seven days, after an incubation period of four to10 days after the bite from an infected mosquito.
Severe dengue is a potentially deadly complication due to plasma leaking, fluid accumulation, respiratory distress, severe bleeding, or organ impairment.
Warning signs occur three to seven days after the first symptoms, in conjunction with a decrease in temperature (below 38°C/100°F) and include: severe abdominal pain, persistent vomiting, rapid breathing, bleeding gums, fatigue, restlessness, blood in vomit.
The next 24–48 hours of the critical stage can be lethal; proper medical care is needed to avoid complications and risk of death.
Dengue hemorrhagic fever tends to affect children under 10 years of age. It causes abdominal pain, hemorrhage (bleeding), and circulatory collapse (shock).