Dengue fever can progress to a severe form known as dengue hemorrhagic fever (DHF) or dengue shock syndrome (DSS). Warning signs of severe dengue include severe abdominal pain, persistent vomiting, bleeding gums, rapid breathing, fatigue, restlessness, blood in vomit or stools, cold or clammy skin, and a decrease in urine output. If any of these warning signs appear, immediate medical attention should be sought, as severe dengue can be life-threatening. Early detection and management are crucial in preventing complications and ensuring proper medical care. It is important to note that not all individuals with dengue infection will develop severe symptoms, but vigilance and monitoring are essential, especially in areas with a high prevalence of dengue.