MEDICAL ANIMATION TRANSCRIPT: Spirometry is a test of how well your lungs are working, by measuring how fast and how much air you can breathe in and out. Normally as you breathe in, or inhale, air moves freely through your trachea, or windpipe, then through large tubes called bronchi, smaller tubes called the bronchioles, and finally into tiny sacs called alveoli. Small blood vessels, called capillaries, surround your alveoli. Oxygen from the air you breathe passes into your capillaries. Then carbon dioxide from your body passes out of your capillaries into an alveolus. You get rid of the carbon dioxide when you breathe out, or exhale. Diseases such as asthma, bronchitis, and pulmonary fibrosis narrow your bronchioles, reducing the amount of air going into your lungs. And diseases such as lung cancer and emphysema damage your alveoli, reducing the amount of oxygen in your blood. These diseases can make it hard for you to breathe. Your doctor may recommend a spirometry test to identify a disease in your lungs, check the severity of your existing lung disease, or to determine if the medications you take are helping. During the test, your caregiver will use a device called a spirometer. A spirometer is a machine that measures the air you breathe out. Before you take the spectrometry test, you will sit in a comfortable chair with your feet flat on the floor. If you have dentures, you may be asked to remove them. For best results, you will be advised to follow your caregiver's instructions exactly. To start, you will raise your head and chin so that you can breathe easily. Next, you will place a clip on your nose to prevent air from coming out of your nostrils. Then, you'll take a deep breath, filling your lungs completely with air, and hold it. You will place the spirometer's mouthpiece between your teeth and tightly seal your lips surround it. Finally, you will blast the air out of your lungs as hard and as fast as you can, continuing to breathe out until your caregiver tells you to stop. If you are an adult, you will blow for at least six seconds. Children 10 years old and under will blow for three seconds. You will need to perform the spirometry test correctly three times to get accurate results.