Alvin Silverstein - Handy Health Guide to Asthma

OUT OF BREATH

Maybe you have come down with the flu or you got a cavity. Perhaps you have asthma or diabetes. Some people need glasses to see better or are allergic to bee stings. These handy guides will help you learn about your health and how all the parts of your body work together to keep you healthy.

About the Author

Dr. Alvin Silverstein is a retired professor of biology at the College of Staten Island, City University of New York. Virginia Silverstein translates scientific Russian and is a professional author. Together they have written more than 200 books for young people. Laura Silverstein Nunn has coauthored more than 100 books with her parents.

Sometimes it can be difficult to catch your breath.

Take a deep breath and let it out. Usually you dont have to think about breathing. In fact, you may not even realize you are doing it. Breathing becomes noticeable when you are running to catch a bus or sick with a cold.

Some people, however, have to think about breathing every single day. Sometimes they have to struggle just to take a breath. These people may have asthma.

Asthma is a condition that causes part of a persons airways (breathing passages) to become narrow, making it hard for air to get through. As a result, the person may have trouble breathing and may cough or wheeze. Tiny bits of dust, mold, or pollen in the air may bring on breathing problems. Air pollution, very cold weather, exercise, or a bad cold can also make it hard to breathe.

Asthma attacks can be very dangerouseven deadly. There is no cure, but there are ways to keep asthma under control. Symptoms can be treated with fast-acting medications. There are also some things that you can do that may prevent asthma attacks from occurring. Before you can understand what happens during an asthma attack, first you need to know how normal breathing works.

Asthma is a common condition, affecting about 20 million Americans. Nearly 9 million of them are children. Children have smaller airways than adults, so asthma can become more serious for them. Health experts say that the number of asthma cases has increased greatly in recent years and is still on the rise.

When you breathe in, or inhale, air comes in through your nose and mouth. The air then passes down into two spongy organs in your chest called lungs, which fill up with air like balloons. Inside the lungs, oxygenan invisible gas that is part of the airpasses into your blood, which carries it to the many cells of the body. Your body needs oxygen to produce the energy you need to do things like running, playing, eating, thinking, and even sleeping. When the cells use oxygen to produce energy, they also make a gas called carbon dioxide. The blood carries carbon dioxide to the lungs, and it is pushed out when you breathe out, or exhale. When you breathe in again, the process is repeated and it brings fresh air into the lungs.

The parts of the body involved in breathing make up the respiratory system. The respiratory system looks a lot like an upside-down tree. The trunk of the treethe main breathing tubeis called the trachea. You can feel the trachea at the front of your throat. The air you breathe goes down your throat into your chest. There the trachea branches into two large tubes called the bronchi. These tubes lead into the lungs. The bronchi each divide into smaller, almost threadlike tubes, called bronchioles, which look like the branches of a tree.

The bronchi and bronchioles are wrapped in bands of muscle. When these muscles relax, the airways widen. When they contract, or tighten, the airways narrow, and less air can flow through. Normally when you breathe, these muscles are loose and relaxed.

Many different body parts work together to help your respiratory system function properly.

The bronchioles lead into millions of tiny balloon-like air sacs in the lungs. These sacs are called alveoli. They look like tiny bunches of grapes, but they are far too small to see without a microscope. This is where the exchange of oxygen and carbon dioxide takes place.

Alveoli look very much like a bunch of grapes.

The airways have built-in defenses to protect the lungs from dust and other particles that may be breathed in from the air. Some particles that enter your nose get trapped in bristly hairs inside your nostrils. Anything that gets past the first line of defense falls into a gooey liquid called mucus that covers the lining of your nose. Mucus is also produced in the airways, and it picks up pollen grains or tiny bits of dust that might have gotten through. Some of the cells lining the airways have tiny hairlike structures called cilia that move back and forth, creating waves in the mucus coating. Like a conveyor belt, the moving mucus sweeps trapped particles up and away from your lungs. The particles leave your body when you blow your nose, sneeze, or cough.

Hairlike cilia line your airways and move particles away from your lungs.

The term asthma is a Greek word meaning panting.

The average person takes 12 to 16 breaths every minute. Thats more than 20,000 breaths each day! You take even more breaths when you exercise or get stressed. But when you sleep, your breathing slows down.

You may think youre blowing hard when youre blowing out the candles on a birthday cake, but the gust of air from a cough or sneeze is even harder. When you sneeze, the air can explode out of your airways at an average speed of 40 miles (64 kilometers) per hour. But some sneezes travel even faster. A record-breaking sneeze was clocked at over 100 miles (160 kilometers) per hour! Thats as powerful as the winds in a hurricane!

It was first used thousands of years ago to describe the wheezing sound that people make when they are having trouble breathing.