An exanthem is a rash or eruption on the skin. "Viral" means that the rash or eruption is a symptom of an infection due to a virus. Many of the infections that cause viral exanthems also can cause ...

How Does the Brain Work? And How Does the Nervous System Work? How do you remember the way to your friend's house? Why do your eyes blink without you ever thinking about it? Where do dreams come from?

It’s normal for people to masturbate (touch or rub their own genitals because they like the way it feels). Some people do it to relieve stress or tension. It’s nothing to be ashamed of or embarrassed ...

We see and hear about hearts everywhere. A long time ago, people even thought that their emotions came from their hearts, maybe because the heart beats faster when a person is scared or excited. Now ...

Earaches are common in kids and can have many causes. Here’s why they happen and what to do when your child complains of ear pain. Give acetaminophen or ibuprofen as needed to ease pain (check the ...

Both the brain and the spinal cord are protected by bone: the brain by the bones of the skull, and the spinal cord by vertebrae, a set of ring-shaped bones. They're both cushioned by layers of ...

How Does Air Enter the Respiratory System? Air enters the respiratory system through the nose or the mouth. If it goes in the nostrils (also called nares), the air is warmed and humidified. Tiny hairs ...

Herd immunity is the idea that when many people are immune to (protected from) a contagious infection, it's harder for that infection to spread in a community. Antibody shots against specific germs ...

Right ventricle (VEN-trih-kul): one of the four chambers of the heart. The right ventricle pumps blood low in oxygen to the lungs. In the lungs, the blood then gets a "refill" of oxygen.

Vomiting can be caused by many things, most commonly gastroenteritis (the "stomach flu"). Vomiting (throwing up) can cause kids to lose fluids, salts, and minerals, so it's important to make sure ...

Girls have lots of questions about the body changes of puberty. When will my breasts grow? What's the "normal" age to get your first period? Watch this video and find out!

Bullying is a big problem. It can make kids feel hurt, scared, sick, lonely, embarrassed, and sad. Bullies might hit, kick, or push to hurt people, or use words to call names, tease, or scare them. A ...