Dengue fever is an acute viral illness characterized by:

1. Fever, often with sudden onset;
2. Severe headache, often described as retro-ocular;
3. Myalgias and arthralgias that can be very severe;
4. Nausea and vomiting;
5. A rash that may present at different stages of the illness, and whose appearance can be variable—it may be maculopapular, petechial, or erythematous. And
6. Hemorrhagic manifestations, which will be discussed in more detail later.

Patients may also report other symptoms, such as itching and aberrations in the sense of taste, particularly a metallic taste. In addition, there have been reports of severe depression after the acute phase of the illness.