A dengue test confirms whether your fever is caused by the dengue virus, and your platelet count shows how severely it is affecting your blood. The three values people see most on a dengue report are the NS1 antigen, the IgM antibody, and the IgG antibody — each tells you something different about the timing and type of infection. Alongside these, the platelet count from a CBC (complete blood count) is watched closely, because in dengue the platelets often fall. This guide explains what each result means in plain language, when to worry, and how dengue is managed.
The Dengue Tests Explained
Dengue is diagnosed with blood tests that look for either the virus itself (the NS1 antigen) or your body's response to it (IgM and IgG antibodies). Which test is useful depends on how many days you have had fever.
| Test | When It's Positive | What It Means |
|---|---|---|
| NS1 antigen | Early — about day 1 to day 7 of fever | Current / acute infection. The best early test. |
| IgM antibody | From around day 4–5 of illness | Recent or current dengue infection. |
| IgG antibody | Appears later than IgM | Usually past infection. Rising quickly with IgM suggests a secondary (repeat) infection. |
What a Positive NS1 Means
A positive NS1 antigen means you currently have an acute dengue infection. NS1 is a protein made by the dengue virus, and it can be detected very early — from about day 1 to day 7 of fever. That early window is why NS1 is the best test for confirming dengue quickly, often before you feel your worst and before antibodies have had time to appear.
One important limitation: as the illness moves past the first week, the NS1 antigen starts to fade while antibodies rise. So a negative NS1 later in the illness does not rule out dengue — if you have had fever for several days, an IgM antibody test becomes more useful. NS1 is about catching the infection early; antibodies are about confirming it a little later.
Dengue IgM vs IgG
IgM and IgG are two antibodies your immune system makes against dengue, but they appear at different times and mean different things.
- IgM antibody appears around day 4–5 of illness. A positive IgM indicates a recent or current dengue infection. It is the antibody that becomes useful once NS1 starts to fade.
- IgG antibody appears later than IgM. A positive IgG alone usually means a past infection — your body met dengue at some point before.
- IgG rising quickly together with IgM points to a secondary (repeat) dengue infection. This matters because a second dengue infection carries a higher risk of severe disease and deserves closer monitoring.
| Result Combination | What It Usually Means |
|---|---|
| NS1 positive | Acute, early infection |
| IgM positive | Recent infection |
| IgG positive only | Past infection |
| IgM and IgG rising together | Secondary (repeat) infection — higher risk |
Platelet Count in Dengue
Platelets are the cells that help your blood clot, and in dengue they often fall. This is why doctors repeat a CBC (complete blood count) daily during a dengue illness — the trend in your platelet count is one of the clearest signs of how the infection is progressing.
| Platelet Count (per µL) | What It Means |
|---|---|
| 150,000 – 450,000 | Normal range |
| Below 100,000 | Needs close monitoring |
| Below 20,000 | High risk of bleeding |
There is a second CBC value to watch alongside platelets: the hematocrit. In dengue, the hematocrit may rise — this is called hemoconcentration, and it happens because plasma (the fluid part of blood) leaks out of the blood vessels. A falling platelet count together with a rising hematocrit is a warning combination that signals plasma leakage and needs prompt medical review.
Dengue Warning Signs
Most dengue is uncomfortable but recovers with rest and fluids. However, a smaller number of cases turn severe — often around the time the fever begins to settle. Knowing the warning signs can be life-saving.
- Bleeding — from the gums, nose, or under the skin (small red or purple spots)
- Severe abdominal (stomach) pain
- Persistent vomiting that won't stop
- Restlessness or unusual lethargy (drowsiness, confusion, hard to wake)
- Rapid breathing
These signs can appear even after the fever comes down, so do not assume the danger has passed just because you feel cooler. If a person with dengue develops any of the above, treat it as an emergency.
Treatment and Care
There is no specific antiviral medicine that kills the dengue virus — treatment is supportive, meaning it helps your body cope while the infection runs its course. The two pillars of care are rest and fluids.
- Fluids and rest. Drink plenty of fluids and rest. Staying well hydrated is one of the most important things you can do at home, because dengue causes fluid loss.
- Paracetamol for fever. Use paracetamol to bring down fever and ease body aches.
- Avoid aspirin and NSAIDs. Do not take aspirin or NSAIDs such as ibuprofen. These increase the risk of bleeding, which is already a danger in dengue.
Most people recover with fluids and rest. But anyone with warning signs, a very low platelet count, or a rising hematocrit needs hospital monitoring, where fluids and blood counts can be watched closely.
Dengue Season in Pakistan
Dengue causes seasonal outbreaks in Pakistan, mainly during the monsoon and post-monsoon months (around August to November). Cases rise sharply in this period, especially in Punjab (Lahore, Rawalpindi) and Karachi, where standing rainwater gives mosquitoes places to breed.
Dengue spreads through the Aedes mosquito, which — unlike the malaria mosquito — bites during the day. That is why daytime protection matters: use repellent, wear covering clothing, and remove standing water (in pots, coolers, tyres, and containers) around the home to cut down breeding sites. During peak season, any high fever should prompt a dengue test.
How Much Do Dengue Tests Cost in Pakistan?
| Test | Approximate Price (2026) |
|---|---|
| NS1 antigen | Rs. 1,000-2,500 |
| Dengue IgM / IgG antibody | Rs. 800-2,000 |
| CBC (for platelet count) | Rs. 400-800 |
During an active dengue illness, the CBC is often repeated daily to track platelets and hematocrit, so budget for more than one CBC.
Track Your Platelet Count Day by Day
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Try MedVault Free →Frequently Asked Questions
What does a positive dengue NS1 test mean?
A positive dengue NS1 antigen means you currently have an acute dengue infection. NS1 is detectable early — from about day 1 to day 7 of fever — which makes it the best early test. A negative NS1 later in the illness does not rule out dengue, because the antigen fades as antibodies rise.
What is the difference between dengue IgM and IgG?
Dengue IgM appears around day 4 to 5 of illness, and a positive IgM indicates a recent or current infection. IgG appears later; a positive IgG alone usually means past infection. When IgG rises quickly together with IgM, it points to a secondary (repeat) dengue infection, which carries a higher risk of severe disease.
What platelet count is dangerous in dengue?
A normal platelet count is 150,000 to 450,000 per microlitre. In dengue, platelets often fall. Below 100,000 needs close monitoring, and below 20,000 carries a high risk of bleeding. The hematocrit may also rise (hemoconcentration) due to plasma leakage — falling platelets with a rising hematocrit is a warning combination.
What are the warning signs of severe dengue?
Warning signs that need urgent care include bleeding (gums, nose, or under the skin), severe abdominal pain, persistent vomiting, restlessness or lethargy, and rapid breathing. These often appear as the fever settles. If any occur, go to a hospital immediately.
How is dengue treated?
There is no specific antiviral — care is supportive with rest and fluids. Use paracetamol for fever, and avoid aspirin and NSAIDs such as ibuprofen because they increase bleeding risk. Most people recover with fluids and rest, but anyone with warning signs or a very low platelet count needs hospital monitoring.