Asthma is a chronic disease of the airways (breathing tubes inside the lungs), in which the airways are prone to inflammation (swelling and irritation), bronchoconstriction (narrowing and spasm) and mucus production. This causes episodes of wheezing, cough, chest tightness, and shortness of breath. Even when symptoms have resolved, the airways in asthma remain hyperreactive, or prone to recurrent symptoms. Symptomatic episodes come and go, with some people being symptom-free for months or years. Some people have asthma symptoms during childhood that improve in adulthood. Others only get symptoms with exercise or during allergy season, or with exposure to irritants like perfume, scented candles or cigarette smoke. Although asthma is chronic and does not ever “go away,” it is considered “reversible” because symptoms can be relieved.
Asthma is quite common, thought to affect 5-10% of the population worldwide, and affects people of all ages. Anyone can have asthma, but it is more common among those who have allergies and skin rashes such as eczema, those with acid reflux (GERD), and those with lower socioeconomic status, and/or living in poor urban areas.
Asthma symptoms include episodes of wheezing, cough, shortness of breath, sputum production, and chest tightness, in varying severity. Not everyone with asthma will exhibit wheezing. Frequently, the only symptom is a chronic cough. Symptoms may be brought on by exposure to irritants in the air(chemicals, vapors, smoke, pollution) , respiratory illnesses such as colds or flu, allergens such as dust, pollen, etc, cold air, exercise, and acid reflux.
Other illnesses can mimic asthma symptoms, such as an acute respiratory illness (bronchitis, flu, pneumonia), chronic lung diseases (chronic obstructive pulmonary disease (COPD), emphysema), heart disease, GERD, tracheal narrowing, vocal cord dysfunction (spasms, narrowing), choking, cystic fibrosis, tumors in the chest or neck, or pulmonary embolism (blood clot in the lungs.) For this reason, it is important to get the correct diagnosis so the appropriate treatment is given.
The diagnosis of asthma is made by the person’s history, symptoms, physical exam, and most importantly, a breathing test called spirometry or pulmonary function. This test can be done at a health care provider’s office. The patient makes several forced exhalations into a machine that records the amount of air expelled and the respiratory effort. Then, a bronchodilator (medicine that causes the airways to relax and open) is given and the test is repeated. If the test shows a certain level of abnormality which improves after the bronchodilator, this confirms the diagnosis of asthma. Other diseases (listed above) must also be ruled-out, and may require other testing such as a chest x-ray, special heart tests, blood tests, ultrasounds, examination of the vocal cords, and others.
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