You do something about twenty times a minute without even thinking about it--you breathe! In fact, every day you take about twenty-thousand breaths. The organs of your body that allow you to breathe are called your lungs.  You have two of them that work together, located in your chest inside the rib cage.  The main purpose of your lungs is to breathe in good air and breathe out bad air. The good air contains oxygen, which your body needs. The bad air is a gas called carbon dioxide, which your body cannot use. When you breathe in through your nose or mouth, air travels down the back of your throat. It passes through your voice box and into your trachea, or windpipe.  Your trachea is divided into two air passage tubes. One leads to your left lung. The other leads to your right lung.  Inside your lungs, oxygen is removed from the air you breathe and pumped into blood cells. Your lungs also get rid of harmful carbon dioxide from these cells. This process takes place inside hundreds of millions of tiny air sacs. Each adult lung is about the size of a football. When they are healthy, your lungs feel a little like a sponge and are pinkish-gray. When lungs are damaged by smoking, they can appear gray or have black spots on them.One disease that is very common in children involves the lungs. It's asthma. Asthma narrows the breathing tubes, making it harder to breathe.   You probably already know that your lungs are important when you swim. But you may not know this--your lungs are the only part of your body that can float on water! Why does asthma make it hard for people to breathe ?
Because those who get asthma are mainly children. Because the breathing tubes are narrowed by asthma . Because asthma damages the lungs. Because asthma is a common disease.