Understanding Dengue Fever

Dengue (pronounced DEN-gee or DEN-gay) is a severe illness that causes joint pain and high fever. It’s caused by a virus that is spread by mosquitoes.

Causes of dengue

Aedes Mosquito

The virus is spread by Aedes mosquitoes. You can get the virus if you travel to an area where the mosquitoes are active. The mosquitoes are most active during and after a rainy season in parts of the world that are tropical or subtropical, such as:

  • South Pacific

  • South Central Asia 

  • Caribbean

  • Central and South America 

  • Africa

Symptoms of dengue

Dengue fever causes severe flu-like symptoms that last 3 to 7 days:

  • Sudden high fever

  • Severe headache

  • Pain behind the eyes

  • Severe joint and muscle pain

  • Nausea

  • Vomiting

  • Swollen glands

  • Rash that appears 3 to 4 days after the start of a fever

In rare cases, a person with dengue fever can develop severe dengue. This is also called dengue hemorrhagic fever. The symptoms appear as the person’s fever begins to go down, and may include:

  • Vomiting that won’t stop

  • Rapid breathing

  • Blood in vomit

  • Bleeding gums

A person with severe dengue may have trouble breathing, severe bleeding, and damage to organs. The illness can lead to dengue shock syndrome. This is very low blood pressure in the body’s organs. This can be fatal, and is a medical emergency.

Diagnosing and treating dengue

See your health care provider if you get sick within a month of returning from travel to a tropical or subtropical area. Tell your provider where and when you traveled. Your provider can diagnose dengue fever with a blood test. He or she looks for the virus or antibodies in your blood.

If you have dengue fever, your treatment will depend on how severe your illness is. Symptoms are most commonly treated with bed rest and fluids. You may be given acetaminophen to reduce fever and pain. Do not take aspirin, ibuprofen, or naproxen.

Preventing dengue

There is no vaccine for dengue fever. The best protection is to prevent mosquito bites. If you are traveling to an area where dengue fever is a risk:

  • Use insect repellent that contains 20% to 30% DEET on your skin and clothing

  • Stay in indoor areas that have screens or air conditioning

  • Use spray insecticide outdoors

  • Put a mosquito net around your bed

When to seek medical care

Call your health care provider right away if you have:

  • Severe abdominal pain

  • Vomiting that won’t stop

  • Blood in your vomit

  • Red patches on your skin

  • Bleeding from your nose or gums

  • Black, sticky stools

  • Pale, cold skin

  • Trouble breathing