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 ...

Heavy metals are elements that are found in soil, water, and the air we breathe. Plants take up these metals as they grow and can end up in the food we eat. Our bodies need some heavy metals (like ...

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 ...

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 ...

What Does the Heart & Circulatory System Do? If you've ever wondered how your heart works, this movie has the answer. And special thanks to the Fred J. Brotherton Charitable Foundation for supporting ...

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 ...

Many things can lead to hearing loss, but often, no cause is found. Hearing loss is more likely if a child: Some hearing problems come on gradually after birth or show up later in life. If you are ...

A night terror (also called sleep terror) is similar to a nightmare, but is far more dramatic. A child having a night terror wakes up screaming and is impossible to ...

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 ...

What Is Breast Reduction Surgery? Breast reduction surgery is a procedure that makes large breasts smaller. It keeps the natural shape of the breast and nipple/areola (small area around the nipple).

Sexually transmitted diseases (STDs) are infections spread from person to person during sex (vaginal, oral, or anal) or close sexual contact. STDs are also called sexually transmitted infections, or ...

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 ...