Dengue is a viral infection spread by the bite of an infected Aedes mosquito. It causes sudden high fever, severe body pain and, in some people, a drop in platelet count.
Go to hospital immediately if you notice
- Severe stomach pain or tenderness
- Vomiting again and again (three or more times in 24 hours)
- Bleeding from the gums or nose, or blood in vomit or stool
- Fast or difficult breathing
- Restlessness, or unusual drowsiness and weakness
- Cold, clammy or pale skin
- Passing very little urine
Overview
Dengue is caused by the dengue virus, which spreads to people through the bite of an infected Aedes mosquito. It does not spread directly from one person to another.
The Aedes mosquito bites mostly during the daytime — early morning and the few hours before sunset. It breeds in clean, still water collected in and around homes, which is why cases rise sharply during and after the monsoon.
Most people recover in one to two weeks with rest and fluids. A small number develop severe dengue, which is a medical emergency. The danger period is usually when the fever starts coming down, around day three to seven of illness.
Symptoms of Dengue
- Sudden high fever, often up to 40°C (104°F)
- Severe headache, especially pain behind the eyes
- Strong muscle and joint pain — this is why it is called breakbone fever
- Feeling sick or vomiting
- Skin rash, usually appearing two to five days after the fever starts
- Mild bleeding such as from the nose or gums
- Extreme tiredness that can last for weeks after recovery
What causes it
- Infection with one of the four dengue virus types (DENV-1 to DENV-4)
- Transmitted by the bite of an infected Aedes aegypti or Aedes albopictus mosquito
- Mosquitoes breed in stored or collected clean water near homes — coolers, pots, tyres, tanks, plant trays and construction sites
Who is at higher risk
- Living in or travelling to areas where dengue is common
- The monsoon and post-monsoon months, when mosquito numbers rise
- Stagnant water in or around the home
- Having had dengue before — a second infection with a different virus type carries a higher risk of severe dengue
Tests and diagnosis
These are the tests doctors commonly use. Which ones you need depends on your symptoms.
- NS1 antigen test — most useful in the first five days of fever
- IgM and IgG antibody tests — useful from about day five onwards
- Complete blood count (CBC) — to track platelet count and haematocrit
- Doctors usually repeat the blood count daily during the risky phase of the illness
Treatment
- There is no specific antiviral medicine for dengue. Treatment supports the body while it fights the infection.
- Rest, and drink plenty of fluids — water, ORS, coconut water, soups and juices.
- Paracetamol is normally used to bring down fever and ease pain.
- Aspirin, ibuprofen and similar painkillers are generally avoided in dengue because they can increase the risk of bleeding. Ask your doctor before taking any painkiller.
- People with warning signs are admitted to hospital so they can be watched closely and given fluids through a drip.
Prevention
- Empty, scrub, cover or dry all water containers once a week — this breaks the mosquito breeding cycle
- Use mosquito repellent on exposed skin during the day
- Wear full-sleeved clothes, and use mesh screens or nets
- Keep coolers, overhead tanks, flower pot trays and terrace items free of collected water
- Support local fogging and source-reduction drives in your area
When should you see a doctor?
See a doctor for any high fever during the dengue season, especially if it comes with severe headache or body pain. Go to a hospital immediately if any warning sign appears — particularly severe stomach pain, repeated vomiting, bleeding, or if the person becomes drowsy or very weak as the fever falls.
Frequently Asked Questions
What are the first symptoms of dengue?
The first symptoms are usually a sudden high fever with a severe headache, pain behind the eyes and strong muscle and joint pain. They typically begin four to ten days after the mosquito bite.
How many days does dengue fever last?
The fever usually lasts about two to seven days. Most people recover within one to two weeks, though tiredness can continue for several weeks afterwards.
Which day of dengue is most dangerous?
The riskiest period is usually day three to seven, around the time the fever starts coming down. Warning signs most often appear during this phase, so monitoring should not stop just because the fever has settled.
Can dengue spread from one person to another?
No. Dengue does not spread by touch, sharing food or being near someone who is ill. It spreads only through the bite of an infected mosquito.
Is a low platelet count always dangerous in dengue?
Not on its own. Doctors look at the platelet count together with the person's symptoms, haematocrit and overall condition. Many people with a low count recover well without a transfusion, which is only needed in specific situations.
Questions to ask your doctor about Dengue
Pick the three that matter most to you and write them down before your appointment. Consultations are short, and almost everyone forgets at least one.
- Which day of the illness am I on, and when is the risky phase?
- Exactly which warning signs should bring me back immediately?
- How much should I be drinking each day?
- Which painkillers should I avoid?
- Do I need repeat blood counts, and how often?
- Should anyone else at home be watched for symptoms?
What this costs, and what is free
Free under the National Center for Vector Borne Diseases Control (NCVBDC).
Government hospitals and sentinel surveillance hospitals provide dengue testing free of charge. Supportive treatment and admission at a government hospital are also free.
Private dengue panels and daily blood counts add up quickly across a week of illness, and hospital admission costs considerably more. Ayushman Bharat may cover admission for eligible families.
Source: National Center for Vector Borne Diseases Control (NCVBDC), Ayushman Bharat PM-JAY, National Health Authority
Prices and scheme rules change. Confirm current details with the hospital or Kendra before you rely on them.