Asthma

• Published in: Health reports Vol. 16; no. 2; p. 43
• Main Authors: Chen, Yue, Johansen, Helen, Thillaiampalam, Satha, Sambell, Christie
• Format: Journal Article
• Language: English
• Published: Statistics Canada 01.03.2005
• Subjects: Allergens; Allergies; Asthma; Disease management; Fumes; Genetics; Health care; Mortality; Occupational exposure; Risk factors; Canada
• ISSN: 0840-6529; 1209-1367

Asthma is a chronic disease, the symptoms of which include cough, shortness of breath, chest tightness and wheeze. Symptoms and attacks (episodes of more severe shortness of breath) usually occur after viral respiratory infections, exercise, or exposure to allergens, irritant fumes or gases.1 These exposures cause inflammation of the airway wall and abnormal narrowing of the airways, which lead to asthma symptoms. Possible risk factors include a family history of allergies, low birth weight, respiratory distress syndrome, frequent respiratory infections, high exposure to airborne allergens in early childhood, and exposure to tobacco smoke.2,3 Among adults, asthma may result from workplace exposure or concurrent exposure to infectious agents, allergens and pollution.2 An asthma attack, with its accompanying feelings of suffocation, breathlessness and loss of control, is frightening and potentially life-threatening. Of people who reported having asthma in 2003, 48% of males and 60% of females also reported experiencing asthma symptoms or asthma attacks in the past 12 months. The likelihood of having had an attack was relatively low among teenagers and the elderly. By contrast, the likelihood was significantly elevated for people with asthma in the 20-to-44 age range, and for women with asthma who were aged 45 to 64. Few people die of asthma, and for both sexes, age-standardized asthma mortality rates have declined sharply since 1985. In 2001, a total of 299 deaths were attributed to asthma. After age 70, considerably more women than men die of the disease, a reflection of the higher asthma mortality rate among older women and the fact that at older ages, women outnumber men.