10 Symptoms of Yellow Fever

Yellow fever is an acute viral infection. You can catch it by being bitten by mosquitoes that are mostly found in Africa and South America; they carry the virus and transmit it into the bloodstream. There are varying degrees of yellow fever in humans. Most people develop none or at least very mild symptoms for the first, early and acute phase, which takes 3-6 days to appear. Usually, the symptoms will dissipate within 7-10 days, this is phase two, but 15% of people with yellow fever will enter the toxic third phase.


Phase one of yellow fever will typically start with a fever. A fever is your body’s way of dealing with foreign bacteria. A high fever is considered anything over 38C (100.4F). You will feel hot and sweaty, but with a clammy touch to the skin. You’ll experience weakness and lethargy and often won’t be able to go about your daily routine. A fever is not always linked to the flu but you can also experience flu-like symptoms with a fever, and it is often prescribed that you have bed rest until it passes. However, a yellow temperature will not pass but begin a cycle of other symptoms of the disease.

Chills and shivers

As a fever continues, you will experience some chills. A chill, or a shiver, is an uncontrollable bodily shake, which can come on suddenly and last for a few seconds up to a few minutes, depending on the course and treatment. This involuntary bodily action is accompanied by a feeling of coldness all over the body, and the desire to curl up and keeps warm. Shivers can sometimes occur without the onset of a fever, but with yellow fever, it is most likely the progression of the high fever as one of the main symptoms of the disease.

Flu-like symptoms

Typical flu-like symptoms include an aching body, a feeling of being unwell and a cloudy mind, even before the congestion starts. This is the coming of a cold or the flu. In the case of yellow fever the symptoms may start similar, but if you particularly feel the aching muscles in the back of your legs, it can be a sign of something more than the flu. This is part of phase one of yellow fever, and if untreated the symptoms become worse and morph into a more serious condition.

Headache and dizziness

Headaches are caused by many factors and can often be lumped into a category that includes fatigue and dizziness and nausea. A severe headache will cause symptoms such as a throbbing or pounding type of pain that affects the entire head, or the pain can shift from one side to the other. Included with the pain may be sensitive to light and noise and blurred vision. When a severe headache or a migraine comes on, most people deal with it by bed rest in a dark room and some paracetamol to help the pain. A migraine from yellow fever virus may start dull and then escalate as the virus escalates in the body.

Slow heart rate

The medical term for a slow heart rate is Bradycardia. A normal heart rate is around 60-100 beats per minute when a person is resting. A heartbeat that is less than 60 beats per minute is considered slower than the normal rate, but still normal and people can function with it at this level. If you have a slow heart rate under 55-50, then there is cause for concern. It can lead to dizziness and fainting and a shortness of breath.


Vomiting is never pleasant, and it’s also something you cannot control. If your body has decided to expel the contents of your stomach, you can’t stop it. You may feel uneasy at first with a sense of nausea sweeping over you, then comes the vomiting. This is a common symptom in the early stages of yellow fever. When you notice blood coming up in the vomit, you’ll need to see a doctor immediately, if you haven’t already, as vomiting blood is phase three in yellow fever and a sign there are worse things to come.

Loss of appetite

A loss of appetite is a normal symptom of a body trying to fight disease. A decreased appetite means you have lost the desire to eat, even if your body needs the nutrients, you simply won’t feel like it because you don’t feel hungry. You can force yourself to eat for the sake of getting some food in your stomach, but when you have lost the will to eat, it is not a pleasant experience. You will also have lost an appetite because of the other symptoms associated with yellow fever, like vomiting and fever.


Getting deeper into the phases of yellow fever, the beginning of phase 3, and also where the disease gets its name from, is the symptom of jaundice. Jaundice is primarily caused when there is too much bilirubin (yellow pigment) in the blood, which is called hyperbilirubinemia. It is caused by damage to the liver and interference with the body’s flow of bile. The skin will have a yellow tinge, and the whites of the eyes will also turn yellow, which means it’s a condition that shows itself. Jaundice alone also brings on fever, blood in the vomit and stool and abdominal pain and tenderness.


When a body goes into medical shock, it is usually a sign of a fall in blood flow. A number of things can cause this, but in the case of yellow fever, it is because the body is having such a quick reaction to the virus and the internal organs are struggling to cope and the stress that the disease puts on the body. Signs that someone is going into shock are a rapid pulse and irregular breathing, dilated pupils and cold skin to touch. If it is not treated as soon as possible, it can lead to worse scenarios such as organ damage because the internal organs and the body’s tissues are not getting enough oxygen.

Internal bleeding

Internal bleeding is a hemorrhaging from the vascular system, (your arteries and veins) into a body cavity, (any fluid-filled space in the body) with no open wound for the blood to escape. Kidney problems that stem from yellow fever can lead to organ failure, which then results in internal bleeding and the accumulation of fluid in the body. Along with all of this going on inside you, you may also have a confused mental state, slip into shock or a coma, have heart failure and ultimately die if you are not treated quickly and properly. Coma and organ failure are in phase 3 of the yellow fever progression, best to catch the warning signs early.