Yellow fever, as it names implies, got its name from two of its two of its most obvious symptoms i.e. yellowing of the human skin and also fever. It is an hemorrhagic medical condition that leads to high fever, skin bleeding, liver or kidney crisis that can eventual lead to death of an individual. It is an acute, systemic disease, meaning that it starts suddenly, and it affects the whole body.

Most people with yellow fever do not develop symptoms, or the symptoms are very mild. The initial symptoms of yellow fever may be indistinguishable from those of malaria, dengue fever, or other viral hemorrhagic fevers. It has an incubation period of between 3 and 6 days, so it takes from 3 to 6 days for signs and symptoms to appear after a person is infected. And this disease cannot spread from one individual to another. Only infection - carrying mosquitoes (i.e. the aedes and haemogogus species) spread the disease to humans.

The main symptoms of yellow fever are a high temperature, a slow pulse, albuminuria, jaundice, congestion of the face, and hemorrhage, or bleeding.

Yellow fever has three stages of symptoms which includes the incubation state; acute stage; and the toxic stage (this is life threatening).

1. Incubation Stage: This is the first stage of yellow fever disease that occurs between 3 – 6 days period. During this particular period, most individuals do not have any form of symptoms or signs to show that they have contracted the disease.
2. Acute Stage: This is the second stage of the yellow fever; and during this period, an individual may experience:

• Fever
• Headache
• Muscle aches, particularly in your back and knees
• Sensitivity to light
• Nausea, vomiting or both
• Loss of appetite
• Dizziness
• Red eyes, face or tongue

These symptoms usually disappear within 7 to 10 days. And they usually improve after a few days, but around 15 percent of people enter the third stage called the toxic stage. The symptoms are more severe, and they may be life-threatening.

3. Toxic Stage: Although signs and symptoms may disappear for a day or two following the acute phase, some people with acute yellow fever then enter a toxic phase. During the toxic phase, acute signs and symptoms return and more-severe and life-threatening ones also appear. These symptoms can include:

• Yellowing of your skin and the whites of your eyes (jaundice)
• Abdominal pain and vomiting, sometimes of blood
• Decreased urination
• Bleeding from your nose, mouth and eyes
• Arrhythmias or irregular heartbeats i.e. slow heart rate (Bradycardia)
• Liver and kidney failure
• Brain dysfunction, including delirium, seizures and coma
• Recurring fever
• Tiredness, sluggishness, lethargy
• Hemorrhage

Between 20 percent and 50 percent of people who develop toxic stage symptoms die within two weeks.

Within 7 to 10 days, yellow fever is fatal in around half of all people who enter the toxic phase. And those who recover do not generally have any organ damage and are immune for life.

[Next Article on Yellow Fever: How To Diagnose Yellow Fever]