Yellow fever is named for two of its main symptoms: Fever and the possibility of jaundice, which causes the skin and eyes to take on a yellowish tinge.

However, this condition can come with many other symptoms including a headache, body aches, vomiting, fatigue, and in severe cases the failure of multiple organs, which can be fatal. Fortunately, most cases never become severe.

yellow fever symptoms — © Verywell, 2018

Frequent Symptoms

Many people who contract a mild case of yellow fever will never even know it because they won't have any symptoms at all. Others with a mild case will get sick between three and six days after they're infected.

Stage 1 Symptoms

Yellow fever either has a single stage or progresses through three stages. Stage 1 is what starts after that three to six day incubation period.

The initial symptoms of yellow fever come on quickly and can include any of the following:

High fever
Chills
A severe headache
Back pain
Widespread body aches
Nausea and vomiting
Lack of appetite
Dizziness
Fatigue
Weakness

These symptoms generally last for just a few days, generally two to four. After that, they go away.

Most people get better and stay better—the disease doesn't progress any further.

But in rare cases, it progresses to further stages, which have their own set of symptoms.

Rare Symptoms

Stage 2

If stage 1 progresses, stage 2 occurs during the time that stage 1 symptoms dissipate and the person feels well for about 24 to 48 hours.

Stage 3

Stage 3 flows in between 6 and 11 days from the initial infection, when symptoms come rushing back. They're not exactly the same, though. Stage 3 symptoms can include:

Return of a high fever
Possible jaundice (yellowing) due to damage to the liver
Fatigue and lethargy
Dark urine
Abdominal pain with vomiting
Bleeding from the gums, nose, eyes, and/or stomach
Bloody stools
Bloody vomit
Easily bruised skin
Confusion
Shock
Kidney, liver, or other organ failure
Irregular heartbeats
Delirium
Seizures
Coma is possible
Death is possible

Between 20 percent and 50 percent of the people who go on to this phase of the disease die within the next week or two.

Complications

Babies and people over 50 years old are more likely than others to develop severe symptoms and to die from yellow fever, making prevention especially important for those age groups. Some people are also just more susceptible than others, and some strains of the disease are more serious than others.

However, in those who survive yellow fever—which is the vast majority of those who are infected—the illness goes away and the organ damage heals.

Some people will have weakness and fatigue that continues for several months, but then they, too, will completely recover.

Once you've had yellow fever, you're generally immune to it and won't be infected again even if you're exposed.

When to See a Doctor

If you've been to a region where yellow fever is a risk and you begin developing stage 1 symptoms, call your doctor for advice on how to take care of yourself.

If you begin to experience symptoms of stage 3, get emergency medical attention right away. There's no specific treatment for this illness but it's important to have proper monitoring and care to prevent the worst-case scenario.

Yellow fever sounds scary, but remember that the toxic stage is rare and most people survive it.

If 100 people contract yellow fever during an outbreak in a city, that means about 15 would move on to stages 2 and 3. Depending on factors like age, susceptibility, the specific strain, and the quality of available medical care, at least three people and possibly as many as seven or eight would die.

While those deaths are tragic, don't forget the big picture. Your odds of survival are high if you do contract the illness. Of course, it's better not to risk it at all, which means getting the vaccine before going into high-risk areas and doing what you can to prevent mosquito bites.

What Causes Yellow Fever?