What is a Fever?

Overview

Sweating. Chills. Headache. Weakness. We've all had a fever. But what is it, exactly? Why do we get them, and when is a fever dangerous? Let's take the mystery out of this common problem.

What is it?

A fever is an increase in your body's temperature. Normally, your body stays right around 98.6 degrees Fahrenheit (37 degrees Celsius). But when this temperature rises, we say you have a fever.

Why does it happen?

A fever is a sign that something is not right within your body. Usually, it means your body is fighting an infection. Your body raises its temperature to help fight off germs. So, a fever is actually part of your healthy immune response. And if your fever is only a few degrees, it's usually not cause for concern for most people. The exception is for babies younger than three months old. In that case, call the doctor.

When is it a problem?

So when is a fever dangerous? Well, if your fever reaches 103 degrees Fahrenheit (39.4 degrees Celsius) or higher, you need to take it seriously. Seek immediate medical attention. And you also need to get help if you have a fever with symptoms such as confusion, difficulty breathing, neck pain and seizures. Ignoring these symptoms can be harmful, or even deadly. For more information, talk to your doctor.