Up until 15 years ago, asthma was considered by physicians to be simply a spastic disease of the bronchial tubes which in turn led to all the other symptoms associated with it. Starting in the 1980s with ever–increasing information and knowledge about asthma, bronchial tube inflammation was considered by most authorities as the basic underlying problem. Inflammation is our body’s response to foreign or toxic substances that enter or come in contact with the body. Inflammation is caused by the arrival of blood and protective cells into the area involved. When a bacterial infection occurs somewhere in our body, white blood cells blood rush to the infected site and try to either destroy the bacteria or isolate and neutralize their harmful effects. This also happens in asthma, where the foreign agent is an allergy causing substance (called an allergen), such as pollen, house dust mites and animal dander. With asthma, the allergen triggers an unwanted and harmful inflammatory reaction, which, like our response to an infection, signals the body to summon blood and white blood cells into the irritated area. The “Inflammatory cells” produce and release chemical substances called mediators which attack the foreign agents or, in this case, the allergen. And in the process of the body trying to defend itself, some damage and changes occur in the tissues of the bronchial tubes. This damage results in the development of easily irritated bronchial tubes, which is called hyper–responsiveness. This condition then causes the lungs to become excessively “Twitchy” and to react (or overreact) to previously non–allergic stimuli, such as cold weather, pollution, dry air and chemical odors. The also–twitchy bronchial tubes will react by going into a spasm, which leads to the symptoms of shortness of breath, coughing, wheezing and chest tightness. This entire process is possibly reversible if caught early in its onset by establishing preventive measures or treating with appropriate medication. In summary, we now recognize asthma as a condition which begins with inflammation of the bronchial membranes which results in changes that bring about bronchial hyper–reactivity, which in turn cause the physical symptoms of wheezing, coughing, shortness of breath and chest tightness, i.e. the classic symptoms of asthma. By learning to recognize the underlying factors and symptoms of asthma, physicians and patients can more adequately control and treat both the causes and effects of asthma.