Healthy Living

What are the Signs and Symptoms of Dengue Fever?

Symptoms to look for when Dengue is strongly suspected

What are the Signs and Symptoms of Dengue Fever?

Key Takeaways

  • The infection occurs when mosquito saliva mixed with harmful viruses gets injected into the bloodstream in search of a blood vessel.
  • Apart from usual symptoms, the skin breaks out into minute petechiae or blood bursts, which are tiny blood capillaries that swell and discharge blood into surrounding tissues.

Entry point: The proboscis prick of the Aedes mosquito

In Dengue fever, the human body plays host to a virus that is carried by the Aedes species of mosquitoes. The infection occurs when mosquito saliva is mixed with harmful viruses in the bloodstream. The virus then goes through stages of overcoming the body’s defensive mechanisms, by infecting the glands before replicating itself in large numbers.


The virus rides the circulatory system

The virus brings about remarkable changes in the walls of the blood vessels making them enlarge and widen, thereby allowing blood and plasma to leak through porous walls into surrounding tissue.

The spleen and lymphatic system suffer damage

The spleen grows in size, due to the infection. The same happens to the lymph nodes that are positioned throughout the lymphatic system. Enlargement of the spleen and lymph tissue follows, and this severely impairs disease fighting white blood cell production in vital tissues. Because of weakened lymph nodes, the fluids that are leaking out of the blood vessels are not immediately replenished. This creates fluid buildup in tissues that swell along with their organs.  

The blood clotting factors get weakened

The virus slows down the working of the blood’s clotting chemicals. As a result, bleeding doesn’t end. This usually marks the beginning of tissue and organ hemorrhage.

Worsening of symptoms following successful virus incubation

Following infection, it takes at least 4 to 7 days for the incubation period during which the virus replicates feverishly.

  • Fever rises steadily and does not subside except with immediate medication like Tylenol that is injected intravenously.
  • Shivering and chills come and go at random.
  • A recurring headache is accompanied by a dull pain behind the eyes.   
  • Uninhibited leakage of plasma into tissue causes localized swelling.  
  • Eyes become reddish and cheeks flush mostly as a result of the swelling of blood vessels beneath the skin.
  • Pain in the lower back, joints and elbows restrict movement much like in arthritis.
  • The body rests in extreme lethargy and has too little energy to do routine work.  

Resurfacing of the ‘Dengue Triad’

In many instances, the disease can last for a couple of days, and the patient breaks out into a heavy sweat as the fever subsides. Only a general sense of tiredness lasts for a week or more. In some cases, the fever returns with stronger intensity and is also accompanied by clusters of reddish bumps that appear all over the body barring the face. A constant headache throbs in the background, and the palms and soles of the feet turn reddish and puff up noticeably. The unmistakable combination of fever, skin rashes, and headaches are referred to by specialists as the significant “Dengue Triad.”

Symptoms are internal and external indicators of the body’s immune response to the virus

Any infection of the Dengue virus protects the body against the same infection for at least a year. This is because the immune system encourages the production of antibodies that recognize and fight the virus. In extreme cases, the immune system overreacts to the presence of the virus in its secondary attack.

Extreme symptom characteristics of immune overreaction

Above and beyond usual symptoms, the skin breaks out into minute petechiae or blood bursts which represent tiny blood capillaries that are swelling and discharging blood into surrounding tissues. This creates a distressed abdomen triggering vomiting of blood, and passage of blood in urine and stools. This kind of immune overreaction which provokes excessive bleeding, is typical of the Dengue Hemorrhagic fever (DHF).  

Dengue shock syndrome (DSS)

The excessive bleeding occurring internally is brought on by the abnormal swelling or distension of minute blood vessels. The larger girth of the blood vessels slows down blood circulation, and seriously deprives vital organs of oxygen. The resulting widespread damage to organs and systems is termed as Dengue Shock Syndrome.