Dengue Haemorrhagic Fever: A Complete Guide to Symptoms & Care
Understand Dengue Haemorrhagic Fever (DHF) with this complete guide on symptoms, warning signs, causes, treatment, and prevention. Learn when dengue becomes life-threatening and how timely care can save lives.
Written by Dr. Dhankecha Mayank Dineshbhai
Reviewed by Dr. Siri Nallapu MBBS
Last updated on 12th Sep, 2025
Introduction
Dengue is a familiar name in many parts of the world, but its severe form, Dengue Haemorrhagic Fever (DHF), is a medical emergency that demands immediate attention. This comprehensive guide breaks down everything you need to know about DHF. We will move beyond the basics to help you understand the critical differences between a typical dengue infection and a severe one, recognise the life-threatening warning signs, and know exactly when to seek professional medical help. Navigating a dengue haemorrhagic fever diagnosis can be frightening, but being informed is your first and most powerful step. This article will equip you with knowledge about symptoms, treatment protocols, and crucial prevention strategies to keep you and your family safe.
What is Dengue Haemorrhagic Fever (DHF)?
Dengue Haemorrhagic Fever (DHF) is not a separate disease but a severe complication of a dengue virus infection. It is characterized by high fever, damage to the lymphatic system, and most critically, leakage of blood plasma from blood vessels into surrounding tissues. This plasma leakage can lead to severe fluid accumulation, circulatory system failure, and shock, known as Dengue Shock Syndrome (DSS), which can be fatal if not treated promptly and correctly.
The World Health Organization (WHO) now classifies DHF as part of "Severe Dengue," emphasising its acute nature. It typically occurs after the initial fever begins to subside, catching many families off guard.
How DHF Differs from Classic Dengue Fever
While both are caused by the same virus, they are vastly different in presentation and risk.
Classic Dengue Fever: Involves high fever, severe headache, pain behind the eyes, muscle and joint pains, and rash. It is often called "break-bone fever" due to the intense pain. It is usually self-limiting and lasts about a week.
Dengue Haemorrhagic Fever (DHF): Includes all the symptoms of classic dengue but progresses to include plasma leakage, haemorrhagic manifestations (bleeding), and often thrombocytopenia (very low platelet count). The defining feature is the leakage of fluid, which differentiates it from simple bleeding disorders.
The Critical Phase: Understanding When Dengue Turns Severe
The course of dengue has three phases: febrile, critical, and recovery. The critical phase is when DHF manifests. It typically begins around the time the fever subsides (days 3-7 of illness). This is the most dangerous period, where plasma leakage can cause fluid accumulation in the chest and abdomen, leading to shock. Close monitoring during this phase is essential for survival.
Recognising the Symptoms: From Mild to Severe
Knowing the progression of symptoms can be life-saving. Early recognition of severe dengue symptoms is the key to preventing tragedy.
Early Warning Signs of Dengue Fever
The initial symptoms are often indistinguishable from a bad flu:
Sudden high fever (104°F or 40°C)
Severe headache, particularly behind the eyes
Intense muscle, bone, and joint pain
Nausea and vomiting
Swollen glands
A widespread skin rash that may appear a few days into the fever
The Danger Signs of Progressing to DHF
As the initial fever breaks, the following warning signs indicate the disease may be progressing to severe dengue or DHF. This is the time to seek hospital care IMMEDIATELY:
Severe and continuous abdominal pain
Persistent vomiting (often with blood)
Bleeding from the nose or gums
Vomiting blood or blood in stools
Rapid breathing or difficulty breathing
Extreme fatigue, restlessness, or irritability
Pale, cold, or clammy skin
Understanding Warning Signs like Severe Abdominal Pain
This isn't just a stomach ache. The pain associated with DHF is often intense and constant, caused by liver enlargement and inflammation, as well as the beginning of plasma leakage into the abdominal cavity.
#What Bleeding and Bruising Really Look Like
Haemorrhagic manifestations aren't always dramatic gushes of blood. Look for subtle signs: easy bruising from minor bumps, petechiae (tiny red spots under the skin that don't fade when pressed), or bleeding from the gums while brushing teeth.
Causes and Risk Factors: Who is Most Vulnerable?
DHF is caused by one of the four closely related dengue virus serotypes (DENV-1, DENV-2, DENV-3, and DENV-4). You become infected when bitten by a female Aedes aegypti mosquito carrying the virus.
The Concept of Antibody-Dependent Enhancement (ADE)
This is a unique and critical risk factor. A person who has previously been infected with one serotype of dengue virus has a significantly higher risk of developing DHF if they later become infected with a different serotype. The existing antibodies from the first infection can actually help the new virus enter cells more easily, leading to a more severe and overwhelming infection. This is why DHF is more commonly observed in children and adults who have had dengue before, rather than in first-time infections.
How is Dengue Haemorrhagic Fever Diagnosed?
Diagnosis is based on a combination of clinical evaluation and specific blood tests. If you suspect DHF, a doctor will look for the classic triad: fever, haemorrhagic manifestations, and thrombocytopenia.
Essential Blood Tests and What They Mean
Complete Blood Count (CBC): This is crucial. A rapidly falling platelet count (thrombocytopenia) and a rising hematocrit level (indicating haemoconcentration due to plasma leakage) are hallmark signs of DHF. For convenient and accurate monitoring, Apollo24|7 offers home collection for CBC tests, allowing you to track your platelet count without multiple hospital visits.
NS1 Antigen Test: Effective for early detection (first 1-5 days of fever) as it identifies the presence of the virus itself.
Serology Tests (IgG and IgM): These tests detect antibodies the body produces to fight the infection. IgM antibodies appear first, indicating a recent infection, while IgG antibodies appear later and indicate a past infection.
Dengue Haemorrhagic Fever Treatment Protocols
There is no specific antiviral cure for dengue or DHF. Treatment is entirely supportive and focuses on managing symptoms and preventing complications.
The Lifesaving Role of Careful Fluid Management
This is the cornerstone of DHF treatment. The goal is to replace fluids lost through plasma leakage without causing fluid overload. This is why hospitalization is often necessary—doctors use intravenous (IV) fluids and meticulously monitor the patient's fluid intake and output,
hematocrit levels, and vital signs.
Medications to Use and Absolutely Avoid
Use: Paracetamol (Acetaminophen) is the preferred drug to manage fever and pain. Tepid sponge baths can also help reduce fever.
AVOID: Non-Steroidal Anti-Inflammatory Drugs (NSAIDs) like Ibuprofen, Aspirin, or Naproxen. These medications increase the risk of bleeding and can worsen haemorrhagic complications. If your condition does not improve after trying these methods, book a physical visit to a doctor with Apollo24|7 to get a confirmed diagnosis and safe treatment plan.
Preventing Dengue and DHF: Your Best Defense
Prevention is infinitely better than cure. Since the virus is spread by mosquitoes, control focuses on eliminating their breeding grounds and avoiding bites.
Effective Mosquito Control at Home and in Your Community
Eliminate Breeding Sites: The Aedes mosquito breeds in clean, stagnant water. Regularly empty, cover, or discard items that hold water (plant saucers, coolers, old tires, buckets).
Prevent Bites: Use mosquito repellents containing DEET, Picaridin, or Oil of Lemon Eucalyptus. Wear long-sleeved shirts and long pants, especially during early morning and late afternoon when these mosquitoes are most active. Use window and door screens and mosquito nets.
Conclusion
Understanding Dengue Haemorrhagic Fever empowers you to act swiftly and wisely. While the disease can be severe, outcomes are excellent with timely medical intervention. The journey from classic dengue to DHF is marked by specific, recognisable warning signs. Remember, the decline of fever is not the end of the illness; it's the start of the most critical window for observation. Prioritise mosquito control to protect your community, and never hesitate to seek professional medical advice at the first sign of severe symptoms. Your health and the health of your loved ones depend on informed awareness and proactive care. If you or a family member are experiencing persistent symptoms and need expert consultation, you can consult a doctor online with Apollo24|7 for immediate guidance.
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Consult Top Specialists
Dr Syed Mateen Pasha
General Physician
2 Years • MBBS
Bengaluru
PRESTIGE SHANTHINIKETAN - SOCIETY CLINIC, Bengaluru
Dr. Anand Ravi
General Physician
2 Years • MBBS
Bengaluru
PRESTIGE SHANTHINIKETAN - SOCIETY CLINIC, Bengaluru
Dr. M L Ezhilarasan
General Practitioner
6 Years • MBBS
Visakhapatnam
Apollo 24|7 Clinic - Andhra Pradesh, Visakhapatnam
Dr. Madhuri Sai Sreepada
General Practitioner
9 Years • MBBS
Hyderabad
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4 Years • MBBS
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Frequently Asked Questions
Can you get Dengue Haemorrhagic Fever on your first infection?
While it's less common, it is possible, especially in infants or individuals with weakened immune systems. However, the risk is significantly higher during a second infection with a different dengue virus serotype.
What is a dangerous platelet count in dengue?
A normal platelet count ranges from 150,000 to 450,000 platelets per microliter of blood. In dengue, counts often drop. A count below 100,000 is a concern, and a rapid drop below 20,000-50,000 significantly increases the risk of severe bleeding and often requires medical supervision and possible transfusion.
How long does it take to recover from DHF?
The acute critical phase lasts about 24-48 hours. After that, the recovery phase begins, where patients often feel extreme fatigue and weakness for several weeks. Full recovery of strength and platelet count can take a month or more.
What are the best foods to eat during dengue recovery?
Focus on hydration and easy-to-digest, nutrient-rich foods. Papaya leaf extract is popularly believed to help increase platelet count, though strong scientific evidence is limited. Other good choices are porridge, soups, herbal teas, fruits like kiwi and pomegranate, and protein-rich foods like dal and eggs.
Is the dengue vaccine effective?
Yes, vaccines exist but their use is targeted. The WHO recommends vaccination primarily for children aged 9-16 who have had a confirmed previous dengue infection living in endemic areas. It is not recommended for those who have never had dengue, due to the risk of ADE.