Hic! Achoo! Ahh! Your body can hiccup, sneeze and yawn. Let's find out what happens inside you each time.

Your diaphragm is a muscle under your lungs that helps you breathe. In a hiccup, the diaphragm jerks, so air rushes in fast. Then your vocal cords snap shut, and that makes the "hic" sound.

Eating too much or too fast can start hiccups. So can fizzy drinks and getting very excited. Most people get hiccups sometimes, and a bout of hiccups usually stops within minutes.

People try many home tricks for hiccups, such as holding their breath, sipping ice-cold water or swallowing a little sugar. These are things people try, not proven cures.

A sneeze is a sudden burst of air that rushes out of your nose and mouth. It helps clear dust and dirt out of your nose. A sneeze is a reflex, which means your body does it on its own. You cannot decide when it happens.

Dust, pollen, spicy food and strong feelings can set off a sneeze.

Sneezes and coughs can spread germs, such as the germs that cause a cold. When you sneeze, cover your nose and mouth with a tissue. If you have no tissue, sneeze into your elbow. Then wash your hands with soap and water. That helps stop germs from spreading.

A yawn is a deep breath in with the mouth wide open. Often the eyes close and the body stretches. People often yawn when they are tired or bored. Other animals yawn too, including cats, dogs, birds and fish.

Yawns are catching. Seeing someone yawn can make you yawn. Even hearing or thinking about a yawn can do it. Dogs can catch a yawn from a person, too.

Why do we yawn at all? Nobody knows for certain. What do you think a yawn might be for?

Words to know

• diaphragm: breathing muscle
• reflex: automatic action
• germs: tiny sickness-spreaders
• pollen: flower dust