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 ...

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 ...

infection in the urinary tract irritation or injury of the genital area stones (small masses of minerals) in the urinary tract Urinary tract infections (UTIs) are the most common cause of pain during ...

Just about every guy wonders how he measures up "down-there." Here's the lowdown for any guy who's ever worried about whether his penis is a normal size. There is a wide range of normal penis sizes.

Walking pneumonia is a less serious form of the lung infection pneumonia. It's often caused by bacteria called Mycoplasma pneumoniae, but other bacteria or viruses can also cause it. Most kids with ...

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 ...

What Is a Tear-Duct Blockage? A tear duct is a small tube that drains tears from the eyes. Tears are made in glands under the eyelids. They wash over the eyes to keep them moist and clean. Then, they ...

Flat feet are feet that do not have an arch. The middle of the foot touches the ground. Feet with no arches is the main sign of flat feet. Sometimes, flat feet can cause foot, ankle, or knee pain.

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 ...

A period is when blood comes out through a girl's vagina. It is a sign that she is getting close to the end of puberty. Puberty is when your body goes from looking like a kid's into looking more like ...

Is it Safe to Use Household Chemicals During Pregnancy? Some household cleaners and chemicals are safe to use during pregnancy while others are not. Chemicals like ammonia and chlorine might cause ...

What Are HIV and AIDS? HIV (human immunodeficiency virus) is a virus that attacks the immune system, the body’s defense against infections. AIDS (acquired immune deficiency syndrome) can happen after ...