What is dengue fever?
Dengue fever is an infection caused by 1 of the 4 viruses called “dengue viruses.” They are related to each other but are not exactly the same. Getting sick with one dengue virus does not protect a person from the others. A person can get dengue fever more than once.
Dengue fever is spread by mosquitoes that carry dengue viruses. People who live in areas where these mosquitoes are common have the highest risk of infection. These areas include southern Asia, Central and South America, and the Caribbean.
What are the symptoms of dengue fever?
Symptoms usually appear 4 to 7 days after a bite from a mosquito that carries the dengue virus. But they can happen up to 2 weeks later. Symptoms usually last 5 to 7 days.
Dengue fever symptoms are different for each person. They can be mild or severe. They can include:
- Fever
- Headache
- Pain behind the eyes
- Joint and muscle pain
- Feeling tired, sometimes for days or weeks
- Rash: This can be flat or have small bumps. It might be itchy. A rash is more common in people who have not been infected with the dengue virus before.
- Stomach problems, such as nausea, vomiting, and diarrhea
- Cough, sore throat, and stuffy nose—the throat might look red.
- Small purple spots on the skin or bowel movements that look black
- Red eyes
- Swollen glands
Children and younger people often have less severe symptoms. People who have had dengue fever in the past and get infected with a different dengue virus have the highest risk of severe symptoms.
A person with severe dengue fever might:
- Have bad belly pain
- Get bruises without bumping into anything. The person might also have small purple spots on the skin
- Vomit blood
- Get nosebleeds
- Have black bowel movements
- Have seizures: A person who has a seizure might pass out, move or behave strangely. For example, they might shake or fall down.
A woman might also have bleeding between her menstrual periods.
Should I see a doctor?
Yes. If you live in a country where dengue fever is common, see a doctor or nurse if you have any of the symptoms.
If you used to live in a country where dengue fever is common and recently went back for a visit, see a doctor or nurse if you have any symptoms of dengue fever. You might have had an infection when you lived there and gotten infected again on your visit. People who visit these countries often should also see a doctor or nurse if they have symptoms.
Is there a test for dengue fever?
Yes. A doctor might be able to tell if you have dengue fever by doing an exam and learning about the symptoms. They can also do blood tests. These tests can show if you have dengue fever or another disease that causes similar symptoms, such as a Zika virus infection.
In countries where dengue fever is common, you might not get a blood test. But doctors can still treat the symptoms if they think you have them.
How is dengue fever treated?
There is no treatment for the virus that causes dengue fever, but doctors can treat the symptoms. Very sick people can be treated in the hospital. Treatments include:
- Blood transfusions: If the infection causes severe bleeding, doctors can give the person blood that someone else has given to the hospital.
- Getting fluids through a tube called an “IV”
Some people are at greater risk of getting sick from dengue fever than others. These people include:
- Pregnant women
- Babies
- Older people
- People who are obese
- People who have diabetes, kidney failure, or certain blood diseases
These people might need to go to the hospital if they get dengue fever. Doctors can watch for severe symptoms and treat them if they happen. People who live alone or far from a doctor’s office or hospital might also need to stay in the hospital. That way, they can be treated right away if they get very sick.
People who are not as sick can usually rest at home. If you have dengue fever, you might need to see a doctor or nurse every day until you get better. The doctor or nurse can do blood tests and check your blood pressure. These checkups are important because dengue fever can cause serious bleeding. Doctors can look to see if this is happening and treat it early if it is.
Is there anything I can do on my own to feel better?
Yes. If the doctor says you do not need to go to the hospital, you can stay home, rest, and drink plenty of fluids. You can also take acetaminophen (sample brand name: Tylenol) to relieve fever and aches.
Do not take aspirin or NSAIDs, such as ibuprofen (sample brand names: Advil, Motrin) or naproxen (sample brand name: Aleve). These medicines can increase the risk of bleeding in people with dengue fever. Never give aspirin or medicines that contain aspirin to children younger than 18 years old. In children, aspirin can cause a serious problem called Reye syndrome.
Can dengue fever be prevented?
Yes. The best way to prevent dengue fever is to avoid the mosquitoes that carry it. Not all countries where dengue fever is common control mosquitoes well. But you can lower your chances of getting dengue fever if you live or travel there. You can:
- Stay inside during the day, when the mosquitoes that carry dengue fever are most active. Buildings with screens and air conditioning are the safest.
- Wear shoes, long-sleeved shirts, long pants, and a hat when you go outside.
- Wear bug spray or cream that contains DEET or a chemical called picaridin. Check the label to make sure. Do not use DEET on babies younger than 2 months.
- On your clothes and gear, use bug repellants that have a chemical called permethrin.
- Drain any standing water near your home, such as wading pools, buckets, and potted plants with saucers. Mosquitoes breed in standing water.
A vaccine for dengue fever is available in some parts of the world. The vaccine should be used only by people who have had dengue fever in the past.
