September, 2012
Asthma is a lung disease that inflames and narrows your airways. Normally, as you 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 your alveoli, so that your lungs can get rid of it when you exhale. Your bronchioles expand when the air is warm, moist, and free of irritants and allergy-causing substances, called allergens. When air is cold or dry, or contains irritants or allergens, your bronchioles contract. If you have asthma, your airways are frequently inflamed and swollen.
Certain substances can cause your inflamed airways to overreact even more, resulting in an asthma attack. Triggers of asthma attacks are slightly different for everyone, but usually include outdoor irritants and allergens such as pollen, smoke, pollution, and cold weather. Indoor irritants and allergens such as mold, pet dander, dust mites, and cockroach droppings. Food allergens such as fish, shellfish, eggs, peanuts, and soy. And conditions such as respiratory infections, stress, strong emotions, and exercise.
The symptoms of an asthma attack include coughing, wheezing, shortness of breath, and tightness in your chest. During an asthma attack, also known as a bronchospasm, the muscles around your airways tighten, and the airway wall becomes more swollen. Your airways also produce thick mucus that narrows them even more, making it hard for you to breathe.
If you have asthma, your doctor may prescribe medications to reduce inflammation in your airways, constriction of the muscles surrounding your airways, or mucus secretion in your airways. During an asthma attack, you may need to use a short-acting rescue medication, called a bronchodilator. This medication causes your airway muscles to relax quickly, and provides symptom relief within minutes.
Since there is no cure for asthma, the goal is to prevent you from having asthma attacks by using long-acting, anti-inflammatory control medications. If you take them every day, they will reduce the inflammation of your airways, making them less sensitive to triggers of asthma attacks.
