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Health Guide Dengue Fever: What You Need to Know A sudden high fever followed by severe body aches, headache or pain behind the eyes can be worrying—especially during periods when dengue is circulating. Dengue is a viral infection spread mainly through the bite of infected Aedes mosquitoes. It is common in tropical and subtropical regions, including parts of India. Many people recover without serious complications, but some develop severe dengue, which can become a medical emergency. Knowing what dengue looks like is important, but there is one point that is easy to miss: a falling fever does not always mean the person is getting better. Warning signs of severe dengue can appear around the time the fever starts to settle. This guide explains the symptoms, causes, testing, treatment, warning signs and prevention measures in simple language. Cause Dengue virus transmitted mainly by infected Aedes mosquitoes. Common Symptoms Fever, headache, body aches, eye pain, nausea and rash. Important Warning Severe symptoms can appear when the fever begins to settle. What Is Dengue Fever? Dengue is an infection caused by the dengue virus (DENV). There are four closely related dengue virus types, commonly referred to as DENV-1, DENV-2, DENV-3 and DENV-4. The virus is mainly transmitted through the bite of an infected Aedes mosquito. These mosquitoes can live around homes and breed in containers or other places where water collects. Not everyone infected with dengue develops symptoms. When symptoms occur, they can range from a short-lived fever and body aches to severe illness requiring hospital care. Most symptomatic infections improve within about one to two weeks, although tiredness can continue for longer. How Does Dengue Spread? The dengue transmission cycle generally happens through infected Aedes mosquitoes: An Aedes mosquito bites a person who has dengue virus in their blood. The mosquito becomes infected. The infected mosquito later bites another person. The virus enters that person's bloodstream. Dengue is therefore not normally spread through ordinary person-to-person contact, such as touching, sharing food or sitting next to someone. However, someone who has dengue can infect mosquitoes that bite them while the virus is circulating in their blood. Preventing mosquito bites around a person with dengue can therefore help reduce further transmission. What Are the Symptoms of Dengue? Dengue symptoms can look similar to other viral illnesses, particularly in the beginning. The most common symptom is fever, often accompanied by other symptoms. 🌡️ High Fever Often develops suddenly. 🤕 Severe Headache Headache can be prominent during the illness. 👁️ Pain Behind the Eyes Eye pain is a commonly reported symptom. 💪 Muscle & Joint Pain Body aches can be significant. 🤢 Nausea or Vomiting Some people experience digestive symptoms. 🔴 Skin Rash A rash may occur during dengue. Symptoms generally develop several days after infection. The incubation period is usually around 4–10 days, while the illness commonly lasts around 2–7 days. Early Dengue Symptoms At the beginning, a person may simply feel as though they have a strong viral infection. Sudden fever Headache Body aches Pain behind the eyes Loss of appetite Nausea Vomiting Weakness Important: Symptoms alone cannot confirm dengue because several other infections can cause similar symptoms. A healthcare professional can determine whether testing is appropriate. Dengue Symptoms in Children Children can develop many of the same symptoms as adults, but younger children may not be able to explain headache, eye pain or body aches clearly. Parents should watch for: Fever Poor appetite Vomiting Unusual tiredness Body aches Rash Irritability Reduced fluid intake Reduced urine output A child who is difficult to wake, has breathing difficulty, persistent vomiting, severe abdominal pain, bleeding or unusual behaviour should receive urgent medical attention. Dengue Warning Signs: When Is It Dangerous? Most dengue infections do not become severe. However, severe dengue can develop quickly and may cause serious bleeding, shock, fluid accumulation or organ problems. 🚨 Seek Urgent Medical Care Severe abdominal pain Significant stomach pain or tenderness. Persistent vomiting Repeated vomiting or inability to keep fluids down. Bleeding Bleeding from the nose, gums, vomit or stool. Rapid or difficult breathing Breathing problems require urgent assessment. Extreme weakness Severe tiredness, weakness or marked deterioration. Changes in alertness Drowsiness, restlessness, irritability or confusion. Do not wait at home if warning signs of severe dengue develop. Severe dengue is a medical emergency. Why Can Dengue Become Dangerous After the Fever Goes Away? This is one of the most important things families should understand about dengue. It is natural to feel relieved when a high fever starts coming down. However, in dengue, the period around defervescence, when the fever decreases, can be when severe disease develops. The Critical Phase The critical phase commonly occurs around 3–8 days after fever begins. Warning signs may appear during or shortly after the fever settles. Therefore, a lower temperature does not automatically mean the danger has passed. If someone with dengue develops any of the following after the fever improves: Severe stomach pain Persistent vomiting Bleeding Breathing difficulty Extreme weakness Restlessness Reduced alertness they should be assessed urgently by a healthcare professional. How Is Dengue Diagnosed? Symptoms can make a doctor suspect dengue, but laboratory testing can help confirm the infection. A healthcare professional may consider: Symptoms and physical examination Recent travel or residence in a dengue-risk area Exposure to mosquitoes Complete blood count and other laboratory findings Dengue-specific testing The type of dengue test used can depend on how many days the person has been ill. Early in illness, tests that detect the virus or its components may be useful; later, antibody-based tests may be considered. Don't diagnose dengue from platelet count alone. A low platelet count can occur with dengue, but it is not enough by itself to prove that someone has dengue. Diagnosis should consider symptoms, examination and appropriate laboratory testing. Is There a Specific Treatment for Dengue? There is currently no specific antiviral medicine that cures dengue. Treatment mainly focuses on supporting the body while the infection runs its course and watching closely for complications. For people with mild dengue, a healthcare professional may recommend: Adequate rest Appropriate fluid intake Oral rehydration solutions when appropriate Paracetamol for fever and pain when suitable Medical follow-up Monitoring for warning signs People who cannot maintain adequate fluid intake, develop warning signs or become clinically unstable may require hospital care. Which Medicines Should Be Avoided During Dengue? This is particularly important because some commonly used painkillers can increase bleeding risk. ✓ Paracetamol Paracetamol (acetaminophen) may be used for fever and pain when appropriate and according to medical advice or product instructions. ⚠ Aspirin & NSAIDs Aspirin and NSAIDs such as ibuprofen should generally be avoided when dengue is suspected because they may increase bleeding risk. Do not combine multiple fever or pain medicines without checking their ingredients. If you are unsure which medicine is suitable, ask a doctor or pharmacist. How Much Fluid Should You Drink During Dengue? Staying hydrated is important, particularly when fever, vomiting or sweating causes fluid loss. Depending on the person's condition, healthcare professionals may recommend: Water Oral rehydration solution Appropriate electrolyte-containing fluids More fluid is not always better. People with severe dengue may require carefully monitored fluid management in hospital. Too much fluid can also be harmful in certain situations. If a person cannot drink enough or is repeatedly vomiting, seek medical advice. How Long Does Dengue Fever Last? Dengue symptoms commonly last around 2–7 days. Many people begin to recover within about a week, although tiredness and weakness may continue for several weeks after the acute illness. Factor Why It Matters Age Children and older adults may require closer monitoring. General health Existing health conditions can affect clinical management. Severity Warning signs or complications can change the course of illness. Hydration Vomiting, fever and poor intake can increase dehydration risk. Even when the fever improves, continue monitoring for warning signs during the critical period. Can You Get Dengue More Than Once? Yes. There are four dengue virus types, and a person can be infected more than once. An infection generally provides long-lasting protection against the same virus type, but protection against the other types is incomplete and temporary. A subsequent infection can carry a greater risk of severe dengue. This is why having dengue once does not mean you are permanently protected against dengue. How Can You Prevent Dengue? The most effective everyday approach is to avoid mosquito bites and reduce mosquito breeding sites. 1 Use Mosquito Repellent Use an appropriate mosquito repellent according to the product's instructions. Products containing ingredients such as DEET or picaridin can help protect against mosquito bites. 2 Wear Protective Clothing When possible, wear clothing that covers your arms and legs. Loose-fitting long sleeves and trousers can reduce exposed skin. 3 Use Window and Door Screens Properly fitted screens can help keep mosquitoes outside the home. Air-conditioned or well-screened rooms can provide additional protection. 4 Use a Mosquito Net Mosquito nets can be useful, especially for babies, children and people sleeping during the daytime. 5 Remove Standing Water Regularly check flowerpot trays, buckets, old tyres, bottles, cans, coolers, water storage containers and other places where water can collect. 6 Keep Surroundings Clean Do not allow discarded containers, tyres or other objects to collect rainwater. Community participation is also important for reducing mosquito breeding sites. Where Can Aedes Mosquitoes Breed? In and around homes, check regularly for water collecting in: Flowerpot trays Buckets Old tyres Bottles Cans Water storage containers Coolers Open tanks Discarded household items Empty, clean or cover containers that can hold water. In India, Aedes mosquitoes can breed in man-made water containers around homes, making household and community-level mosquito control important. What Should You Do If Someone at Home Has Dengue? If someone in your family has dengue, protecting them from additional mosquito bites is important. During the period when dengue virus is circulating in the blood, an Aedes mosquito can acquire the virus from an infected person and later transmit it to someone else. Use mosquito repellent as appropriate. Use screens or mosquito nets. Remove standing water around the home. Encourage the patient to rest and drink appropriate fluids. Follow the healthcare professional's instructions. Watch closely for warning signs. When Should You See a Doctor for Dengue? Speak with a healthcare professional if you develop a fever with symptoms such as: Severe headache Body aches Pain behind the eyes Nausea or vomiting Rash Significant weakness Medical assessment is especially important for: Young children Older adults Pregnant people People with significant medical conditions People unable to drink enough fluids Anyone who develops warning signs 🚨 Get Urgent Medical Help Seek urgent medical care if there is severe abdominal pain, persistent vomiting, bleeding, breathing difficulty, extreme weakness, altered alertness or other warning signs of severe dengue. Final Takeaway Dengue is usually a self-limiting viral infection, but it should not be taken lightly. The key is to know the difference between common dengue symptoms and warning signs of severe dengue. Fever, headache, body aches, pain behind the eyes, nausea and rash are common symptoms. Severe abdominal pain, persistent vomiting, bleeding, breathing difficulty, extreme weakness or changes in alertness require urgent medical attention. Remember: The fever going away does not always mean the illness is over. Continue monitoring the person during the period when severe dengue can develop. You can also reduce your risk by preventing mosquito bites and removing standing water where Aedes mosquitoes can breed. Have Fever or Dengue Symptoms? If you have persistent fever, severe body aches, vomiting or other concerning symptoms, speak with a qualified healthcare professional for appropriate evaluation. Contact Us Frequently Asked Questions About Dengue What are the first symptoms of dengue? The first symptoms commonly include sudden fever, headache, pain behind the eyes, muscle and joint pain, nausea, vomiting and sometimes a rash. These symptoms can resemble other viral infections. How many days does dengue fever last? Dengue symptoms commonly last around 2–7 days. Many people recover within about a week, although tiredness can continue for longer. What are the warning signs of severe dengue? Severe abdominal pain, persistent vomiting, bleeding, rapid or difficult breathing, extreme weakness, restlessness and changes in alertness are important warning signs requiring urgent medical attention. Can dengue be treated at home? Some people with mild dengue can be managed at home under medical guidance with rest, appropriate fluids, fever control and close observation. Warning signs require urgent medical assessment. Which medicines should be avoided during dengue? Aspirin and NSAIDs such as ibuprofen should generally be avoided when dengue is suspected because they may increase bleeding risk. Paracetamol may be used for fever and pain when appropriate. Does a low platelet count always mean dengue? No. A low platelet count can occur with dengue but is not enough by itself to diagnose the infection. Doctors consider symptoms, examination and appropriate laboratory tests. Can dengue happen twice? Yes. Because there are four dengue virus types, a person can be infected more than once. A later infection with another type can carry a greater risk of severe disease. How can I prevent dengue at home? Use mosquito repellent, wear protective clothing, use screens or mosquito nets where appropriate and regularly remove or cover containers that collect water. Explore More Health Guides Read more practical health information and medical education guides from Digital Facilities. Digital Facilities Health & Medical Guides Article Information Written By Health Content Writer Medically Reviewed By | Last Reviewed: September 2026 Next Review: September 2027 Trusted Medical Sources World Health Organization (WHO) — Dengue and severe dengue World Health Organization (WHO) — Dengue and severe dengue: Questions and Answers Centers for Disease Control and Prevention (CDC) — Clinical Care of Dengue Centers for Disease Control and Prevention (CDC) — Preventing Dengue Medical Disclaimer This article is for general health education and does not replace a consultation, diagnosis or treatment plan from a qualified healthcare professional. If you have symptoms of dengue, particularly persistent fever or warning signs such as severe abdominal pain, persistent vomiting, bleeding, breathing difficulty or changes in alertness, seek appropriate medical care promptly.

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