Dengue fever is an illness from mosquito bites that happen in tropical and subtropical areas of the world. Mild dengue fever causes a high fever and flu-like symptoms. A more serious form of dengue fever, called dengue hemorrhagic fever, can cause bleeding, a sudden drop in blood pressure and death.

Symptoms
Symptoms most often begin 4 to 10 days after a bite from an infected mosquito. The symptoms often are thought to be symptoms of another illness, such as the flu. Dengue fever causes a high fever of 104 degrees Fahrenheit (40 degrees Celsius).
Other symptoms may include:

• Headache
• Muscle, bone or joint pain
• Upset stomach
• Vomiting
• Pain behind the eyes
• Swollen glands
• Rash

Most people get over dengue fever within a week or two. But they may feel tired for a few weeks. For some people, symptoms get worse and can become life-threatening. This is called severe dengue fever, dengue hemorrhagic fever or dengue shock syndrome. Symptoms may include:

• Bad stomach pain
• Repeat vomiting
• Bleeding from the gums or nose
• Blood in the urine, stools or vomit
• Bleeding under the skin, which might look like bruising
• Hard or fast breathing
• Tiredness
• Being cranky or restless

Risk factors
You have a greater risk of getting dengue fever or a more severe form of the infection if:
You live or travel in tropical areas such as Southeast Asia, the western Pacific islands, Latin America and Africa.
Having had dengue fever in the past raises the risk of bad symptoms if you get dengue fever again.

Prevention
If you live in or travel to an area where dengue fever is common, these tips may help lower your risk of mosquito bites:

• Stay in air-conditioned places or housing that has screens on all the windows and doors: The mosquitoes that carry the dengue viruses are most active from dawn to dusk.
• Wear clothing that covers your skin: When you go into areas where there are many mosquitoes, wear a long-sleeved shirt, long pants, socks and shoes.
• Use a substance that keeps mosquitoes away, called repellent: You can put a repellent called permethrin on your clothing, shoes, camping gear and bed netting. For your skin, use a spray, cream, lotion that can repel mosquitoes.
• Give mosquitoes fewer places to breed: The mosquitoes that carry dengue viruses mainly live in and around houses. They breed in standing water that can collect in such things as used car tires. You can help lower the number of mosquitoes near your house by getting rid of places where they lay their eggs.