Asthma is a condition that affects the airways – the small tubes that carry air in and out of the lungs. If you have asthma your airways are almost always sensitive and inflamed. When you come in to contact with something you are allergic to, or something that irritates your airways (a trigger), your airways will become narrower, making it harder to breathe. The muscles around the walls of your airways tighten. The lining of the airways becomes inflamed and starts to swell and often sticky mucus or phlegm is produced. This will lead to you experiencing asthma symptoms.

Asthma is a disease of the respiratory system. Your respiratory system is made up of your nose and mouth, your windpipe (also called your trachea), your lungs, and a bunch of air tubes (or airways) that connect your nose and mouth with your lungs. These tubes are called bronchi and bronchioles. Asthma is a chronic condition. Air trapped in the lungs causes its hallmark symptom: tightening of the chest and difficulty in breathing.

These symptoms are not always continuously present. They come in episodes set off by various environmental or emotional "triggers." Triggers include -- but aren't limited to -- chemicals, pollution, pollen, animal dander, tobacco smoke, and stress.

Some people with asthma have only mild and infrequent episodes. For them, the condition is an occasional inconvenience. For others, episodes can be frequent and serious. They may need emergency medical treatment. If you have asthma, you should have regular checkups by a doctor.

An episode may pass quickly or last more than a day. Sometimes symptoms recur suddenly and with surprising intensity. This "second wave" attack can be more severe and dangerous than the initial episode and may last days or even weeks.

Don't wait to get emergency medical assistance when you're having a serious attack. By knowing your triggers, you can learn to lessen the intensity and frequency of asthma attacks. You may even be able to completely avoid them.

Asthma affects between 15 million and 16 million Americans. More children have asthma than adults. It's the leading cause of school absenteeism and pediatric hospital admission. Although asthma is seldom fatal, it is quite serious. If you have asthma, you should seek the help of a doctor before trying alternative therapies.

Some people with asthma can't tell when they are becoming short of breath. It's called "low perception of dyspnea" or low POD. This makes it hard for them to use their inhalers or call for help when a bad attack is underway. A lung specialist can test you to find out whether you have low POD. Knowing this can save your life.