Warning signs that your dengue infection is getting worse
17 February 2025
Learn the warning signs that indicate your dengue infection is getting worse and when to seek medical help.

Feeling nauseous or feverish? Or have a headache that aches from behind the eyes?
If you suspect you have dengue, check if you have the symptoms below, and look out for the warning signs that the infection is getting worse.
What Are the Common Symptoms of Dengue Fever?
Common symptoms of dengue fever are:
Fever
Headache with pain behind the eyes
Muscle and joint aches
Rash
Nausea and vomiting

The Three Phases of Dengue and Their Warning Signs
Dengue is a dynamic disease – which means that its status changes rapidly over time.

Phase 1: High fever
Dengue typically starts off with high fever, accompanied by body aches and pain.
The fever typically lasts for 3-5 days.
Phase 2: Critical period
The second phase is known as the critical period, and it is the most crucial one to look out for. Your body temperature is coming down (below 38 degrees C), lasting for 48 hours.
During this period, your body experiences fluid shifting out of circulation compartments to other body compartments. Fluid may then accumulate in the lungs or abdominal space.
Your heart rate, blood pressure may fluctuate, and in severe cases, drop to very low levels that damage your vital organs, such as your kidney and liver.
Dengue Warning Signs That Require Immediate Medical Attention
Abdominal pain, that is not hunger pangs
Persistent vomiting, even with just fluids
Bleeding tendencies, such as:
Blood in your vomit (i.e. red streaks of blood)
Bleeding from your nose or gums
Easy bruising
Black and sticky (tar-like) stools
Breathing difficulties
Phase 3: Recovery
After the critical period comes the recovery phase.
During this period, fluids that have shifted out of circulation during the critical phase will return to circulation. In occasional cases, this can lead to fluid overload.
What to Do if You Think You Have Dengue
If you suspect you have dengue fever, seek medical attention immediately.
Based on your symptoms, the doctor will evaluate if further investigations, such as blood tests, are needed.
For more information about dengue, please visit the National Environment Agency website (opens in new tab).
