Severe dengue: What does the disease course look like? 

The majority of people infected with the dengue virus show no or mild symptoms, but around 1 in 20 infections lead to a very serious illness called severe dengue.1, 2   


Symptoms can start suddenly and tend to follow 3 phases:2, 3  


The disease course of severe dengue begins 4-10 days after being bitten by an infected mosquito. 


  • Febrile   

  • Critical  

  • Recovery  


  • As with some mild dengue infections, the severe form usually starts with a high temperature, which lasts for 2–7 days2  

  • Warning signs of progression to severe dengue can occur late in the Febrile Phase, around the time the fever starts to subside2  


  • The critical Phase typically lasts 24-48 hours

  • After the Febrile Phase, those infected can appear well.3 However, a small proportion of people then deteriorate and enter the critical phase2,3 

  • In some cases, the critical phase can be fatal2,3 


  • In most cases. Recovery starts to occur after around 2-3 days3 

  • At this point though, the worst of the symptoms have passed and the road to recovery can begin2,3  

  • Even after recovery, some people may experience profound fatigue for several weeks3   

If you are worried about dengue fever or severe dengue, please consult a healthcare professional as soon as possible. Early detection of disease progression and access to proper medical care can lower fatality rates of severe dengue to below 1 in 100 cases.1

  1. World Health Organization. Dengue and Severe Dengue . Available at: Accessed March 2023. 

  1. Centers For Disease Control And Prevention. Dengue: Clinical Presentation. Available at: Accessed July 2023.

  1. Simmons, CP. Et al. N Engl J Med. 2012;366:1423-32. Available at: Accessed March 2023  

  1. Chagas, GCL. Et al. Trop Med int Health. 2022;27:656-668. Available at: Accessed March 2023.