Condition Guide

Dengue Fever

Name: Dengue Fever: Symptoms & Platelet Count | HealthReview
Creator: Suman Konda
Published: 2026-07-05

Dengue is a viral illness spread by Aedes mosquitoes. Knowing the warning signs and understanding your blood test results, especially platelet count, can be life-saving.

Written by Suman Konda, PharmD, Clinical Pharmacist · Based on peer-reviewed sources · Editorial policy · Not medical advice

Last updated: 01 August 2026 · How we check our content

What is dengue fever?

Dengue fever is a mosquito-borne viral infection caused by the dengue virus (DENV), transmitted by Aedes aegypti and Aedes albopictus mosquitoes. An estimated 390 million infections occur worldwide each year, of which around 96 million produce clinical illness, primarily in tropical and subtropical regions. Most cases cause a self-limiting febrile illness lasting 5–7 days. A small proportion progress to severe dengue (dengue haemorrhagic fever or dengue shock syndrome), which can be life-threatening without prompt hospital care.

Symptoms of dengue fever

Symptoms typically appear 4–10 days after a mosquito bite and include:

Sudden high fever (39–40°C / 102–104°F)
Severe headache, especially behind the eyes
Intense muscle and joint pain ("breakbone fever")
Skin rash: appears 2–5 days after fever starts
Nausea and vomiting
Fatigue and general weakness
Mild bleeding: nose bleeds, gum bleeding, easy bruising

⚠ Warning signs: go to hospital immediately

Severe abdominal pain or tenderness
Persistent vomiting (3+ times in 24 hours)
Bleeding from gums, nose or in vomit/stool
Rapid breathing or difficulty breathing
Feeling very restless, confused or drowsy
Platelet count below 20,000/µL

Dengue blood tests explained

Test	When to use	What it detects
NS1 Antigen	Day 1–5 of fever	Dengue virus protein: best early test
IgM antibody	Day 5 onwards	Recent dengue infection
IgG antibody	Secondary infections	Past dengue exposure
CBC (Platelet count)	Daily monitoring	Falling platelets = dengue progression
Haematocrit (PCV)	Daily monitoring	Rising haematocrit = plasma leakage (danger sign)

Platelet count in dengue

Platelet Count	What it means	Action
> 100,000/µL	Mild drop	Monitor daily, rest at home if no warning signs
50,000–100,000/µL	Moderate drop	Hospital assessment recommended
20,000–50,000/µL	Severe drop	Hospital admission required
< 20,000/µL	Critical	Platelet transfusion may be needed

What to do if you have dengue

Rest: Complete bed rest is essential during the febrile phase
Hydration: Drink at least 2–3 litres of fluids daily, oral rehydration salts (ORS), coconut water, clear broth, fruit juices
Paracetamol only: Take paracetamol (acetaminophen) for fever and pain, do NOT take ibuprofen, aspirin or diclofenac (they increase bleeding risk)
Monitor platelet count: Daily CBC from day 3 of fever
Watch for warning signs: Go to hospital immediately if any danger signs appear
Mosquito control: Use mosquito nets and repellent to prevent spreading dengue to others

There is no specific antiviral treatment for dengue

Treatment is supportive: managing fever, maintaining hydration and monitoring for complications. Dengue vaccines exist (Dengvaxia) but are only approved for people with previous dengue infection. Research into better vaccines continues. Prevention through mosquito control remains the most important public health tool.

Questions to ask your doctor

Should I be admitted to hospital with this platelet count?
How often should I recheck my CBC?
When is it safe to return to work or school?
Can I give dengue to family members at home?

References

The clinical information on this page is based on peer-reviewed sources indexed in PubMed, the biomedical literature database of the US National Library of Medicine.

Bhatt S, Gething PW, Brady OJ, et al. The global distribution and burden of dengue. Nature. 2013;496(7446):504-7. doi:10.1038/nature12060 · PMID 23563266