Medically reviewed by Dr. Hafiz Muhammad Haseeb, M.B.B.S., F.C.P.S. (Haematology), Consultant Haematologist, Al-Nasar Lab & Diagnostic Centre. Updated August 2026.
Quick answer: The dengue test you need depends on how many days you have had fever. NS1 antigen is the right test in the first 1 to 5 days. IgM antibody becomes reliable from about day 5 onward. IgG helps identify a past or repeat infection. A CBC is done alongside to track your platelet count.
What is a dengue test?
A dengue test is a blood test that confirms whether a fever is caused by the dengue virus, which spreads through the bite of an infected Aedes mosquito. Because early dengue looks very similar to typhoid, malaria, flu and other seasonal fevers, testing is the only reliable way to tell them apart and begin correct monitoring.
Which dengue test do you need, and when?
Timing is the single most important factor in dengue testing. A test taken on the wrong day can come back negative even when you do have dengue.
| Test | Best time to take it | What it tells you |
|---|---|---|
| Dengue NS1 Antigen | Day 1 to day 5 of fever | Detects the virus protein directly and confirms a current, early infection |
| Dengue IgM Antibody | From day 5 onward | Shows your immune system is responding to a recent or current infection |
| Dengue IgG Antibody | Day 10 onward (or early in a repeat infection) | Indicates past exposure or a second dengue infection |
| CBC (Complete Blood Count) | At diagnosis, then repeated | Tracks platelet count and haematocrit, the key safety markers |
When should you get tested for dengue?
Get tested if you have had fever for more than 24 to 48 hours during dengue season, especially with severe headache, pain behind the eyes, muscle and joint pain, nausea, or a skin rash. In Lahore, dengue transmission typically rises after the monsoon, so fevers in August through November deserve prompt testing rather than a wait-and-see approach.
Why is a CBC important in dengue?
Confirming dengue is only the first step. What actually determines how serious the illness becomes is your platelet count and haematocrit, both measured by a CBC. Platelets often fall between days 3 and 7, sometimes sharply. Because of this, doctors usually ask for a repeat CBC every 24 to 48 hours during the critical phase, not just once.
Dengue warning signs that need immediate medical attention
Most dengue cases recover at home with rest and fluids. However, go to a hospital straight away if you notice any of the following, particularly as the fever starts to settle:
- Severe or persistent abdominal pain
- Repeated vomiting, or inability to keep fluids down
- Bleeding from the gums or nose, or blood in vomit or stool
- Extreme lethargy, restlessness or confusion
- Cold, clammy skin or difficulty breathing
- A rapidly falling platelet count on your report
The period just after the fever breaks is when severe dengue most often develops, so this is not the time to relax monitoring.
How to prepare for a dengue test
No fasting is required for dengue testing. It is a simple blood sample taken from a vein in your arm. Bring a note of the exact day your fever started. This genuinely changes which test is appropriate, and sharing it helps avoid a false negative result.
Dengue testing at Al-Nasar Lab
Al-Nasar Lab & Diagnostic Centre offers dengue NS1, IgM, IgG and CBC testing across its Lahore network, with home sample collection and same-day digital reports, under PHC accreditation. Home collection is particularly useful in dengue, when repeat CBCs are needed and travelling with a high fever is difficult.
You can book at our main Johar Town campus or any collection centre across Lahore, or arrange home sampling on 0309 1166944.
Frequently Asked Questions
Can a dengue test be negative even if I have dengue?
Yes. This usually happens when the test is taken at the wrong stage of illness, for example an IgM test in the first two days, or an NS1 test after day five or six. If symptoms continue, your doctor may repeat testing after a couple of days.
Do I need to fast before a dengue test?
No. Fasting is not required for NS1, IgM, IgG or CBC testing.
How long does a dengue report take?
Dengue NS1 and antibody results are typically available the same day at Al-Nasar Lab, with reports delivered digitally.
Can I get dengue more than once?
Yes. There are four dengue virus serotypes, and infection with one does not protect you from the others. A second infection carries a higher risk of severe dengue, which is why IgG testing and careful monitoring matter.
What platelet count is dangerous in dengue?
Platelets below 100,000 per microlitre need close monitoring, and counts below 20,000 are considered high risk. However, the trend over time and your symptoms matter more than any single number, so always interpret results with your doctor.
This article is for general information and is not a substitute for medical advice. If you have a fever, please consult a qualified doctor.
Explore our full range of laboratory tests or contact Al-Nasar Lab to book a dengue test in Lahore.
