Dengue Fever

Overview

Dengue fever is a viral infection spread to people through the bite of infected mosquitoes. It is common in many tropical and subtropical regions, especially in areas where the mosquitoes that carry dengue can breed in standing water. Dengue can affect people of all ages, including travelers, expatriates, and local residents.

Most dengue infections are mild to moderate and improve with appropriate medical advice and supportive care. However, dengue can sometimes become severe and lead to complications such as bleeding, dehydration, or problems with circulation. Because symptoms can resemble other infections, medical evaluation is important, especially for people who have recently been in an area where dengue is present.

Symptoms

Symptoms usually begin several days after a mosquito bite, although many people may not remember being bitten. Dengue symptoms can vary from mild illness to severe disease. Common symptoms include:

• Sudden high fever
• Severe headache
• Pain behind the eyes
• Muscle, joint, or bone pain
• Nausea or vomiting
• Skin rash
• Fatigue or weakness
• Mild bleeding, such as nosebleeds or bleeding gums

Some people develop warning signs as the fever begins to improve. These signs may indicate a higher risk of severe dengue and require urgent medical attention. Warning signs include severe abdominal pain, persistent vomiting, difficulty breathing, unusual drowsiness or restlessness, cold or clammy skin, bleeding, or feeling faint.

Causes and Risk Factors

Dengue is caused by the dengue virus, which is transmitted mainly by Aedes mosquitoes. These mosquitoes often bite during the day and can live in and around homes, hotels, offices, and urban areas. They breed in small amounts of standing water, such as water collected in containers, plant pots, buckets, or discarded items.

Risk factors for dengue include living in or traveling to regions where dengue is common, especially during rainy seasons or outbreaks. People who spend time outdoors during mosquito activity hours may have increased exposure. Previous dengue infection can also affect the risk of developing more severe illness with a later infection by a different dengue virus type.

Dengue is not usually spread directly from person to person through casual contact. The main route is through mosquito bites. In rare situations, other forms of transmission may occur, but mosquito control and bite prevention remain the most important public health measures.

Diagnosis

A doctor evaluates dengue based on symptoms, travel or residence history, mosquito exposure, and physical examination. Because dengue can look similar to other infections, laboratory testing is often needed to support the diagnosis and to check for possible complications.

Blood tests may be used to detect the virus or the body’s immune response to infection. Other blood tests may assess blood cell levels, fluid balance, liver involvement, and signs of bleeding risk. In some cases, repeated testing is needed because results can change during the course of the illness.

It is important for patients to tell the healthcare team about recent travel, countries visited, timing of symptoms, previous dengue infection, pregnancy, chronic medical conditions, and any medicines or supplements being used. This information helps guide safe evaluation and monitoring.

Treatment Options

There is no specific antiviral treatment that eliminates dengue virus. Care is mainly supportive and focuses on monitoring symptoms, maintaining hydration, controlling fever and discomfort safely, and detecting warning signs early. The exact approach depends on the person’s age, overall health, symptoms, test results, and risk of complications.

Many patients can be managed with medical guidance and observation, while others may require hospital care. Hospital treatment may include careful fluid management, close monitoring of blood tests, and support for complications if they occur. Severe dengue requires prompt medical attention and may need care in a setting where vital signs, circulation, and bleeding can be closely managed.

Patients should avoid using medicines without medical advice, especially if dengue is suspected, because some medicines can increase bleeding risk. A healthcare professional can recommend the safest options for fever or pain relief based on the individual situation.

Prevention is also important. Measures include reducing mosquito breeding sites, using protective clothing, staying in screened or air-conditioned rooms when possible, and using mosquito repellents as advised by public health guidance. In some countries, dengue vaccination may be available for selected groups, but suitability depends on local recommendations and personal medical history.

When to See a Doctor

Seek medical advice if you develop fever, rash, severe headache, eye pain, muscle or joint pain, nausea, or unusual fatigue after being in an area where dengue occurs. Early evaluation is especially important for children, older adults, pregnant people, and those with chronic health conditions.

Urgent medical care is needed if any warning signs appear, including severe abdominal pain, repeated vomiting, bleeding from the nose or gums, blood in vomit or stool, difficulty breathing, extreme weakness, confusion, fainting, or cold and clammy skin. These signs can occur even when the fever is decreasing.

International patients and travelers should inform healthcare providers about recent destinations and dates of travel. Prompt medical assessment helps distinguish dengue from other infections and supports safe monitoring and care.