Dengue Fever



An infected mosquito passes the virus through a bite to the skin. The virus enters the blood. It spreads throughout the body.

Mosquito Bite
Mosquito bite
Copyright © Nucleus Medical Media, Inc.

Risk Factors

The risk for dengue fever higher for those who live in or travel to:

  • Southeast Asia
  • Western Pacific
  • Americas
  • Eastern Mediterranean
  • Africa



Some people do not have symptoms. Others may have a mild, flu-like illness. Symptoms may be:

  • Fever and chills
  • Headache or eye pain
  • Muscle or bone pain
  • Red or purple spots in skin
  • Minor bleeding in the nose or gums
  • Nausea or vomiting

Serious signs are:

  • Severe belly pain
  • Frequent vomiting
  • Bleeding from the gums or nose that is hard to stop
  • Black tarry stools or blood in the urine (pee)
  • Tiredness or restlessness
  • Problems breathing
  • Pale, cold, or clammy skin
  • Feeling faint

A serious infection can lead to shock and organ failure.


The doctor will ask about your symptoms, and health and travel history. A physical exam and blood tests may be done.

A tourniquet test may be done to check for bleeding under the skin. This test uses an inflated blood pressure cuff on the upper arm for 5 minutes.



Treatment depends on how severe the illness is. Some will need hospital care. Treatment may include rest and replacing fluids by mouth or IV.

A blood transfusion may be given if there is severe bleeding.


The risk of infection may be reduced by mosquito control measures. A dengue vaccine is available in some countries.

This content is reviewed regularly and is updated when new and relevant evidence is made available. This information is neither intended nor implied to be a substitute for professional medical advice. Always seek the advice of your physician or other qualified health provider prior to starting any new treatment or with questions regarding a medical condition.

Edits to original content made by Denver Health.