Asthma is a common chronic inflammatory disease of the airways characterized by variable and recurring symptoms, bronchospasm, and reversible airflow obstruction.
Common symptoms of asthma include wheezing, shortness of breath, chest tightness and coughing. Symptoms are often worse in the early morning or at night. They can also be triggered in response to exercise or cold air. Some people with asthma only rarely experience symptoms, usually in response to triggers, where others may have marked persistent airflow obstruction.
Treatment of acute symptoms are usually with an inhaled short-acting beta-2 agonist. Symptoms can be prevented by avoiding triggers, such as allergens and irritants, and by inhaling corticosteroids.
As of 2009, 300 million people were affected worldwide.
Brittle asthmas are distinguishable by recurrent, severe attacks. Type 1 brittle asthma refers to asthma with wide peak flow variability, despite intense medication. Type 2 brittle asthma describes background well-controlled asthma, with sudden severe exacerbations.
When a patient is having an acute asthma exacerbation, it is commonly referred to as an asthma attack. Symptoms can include shortness of breath, wheezing, and chest tightness. Some people present primarily with coughing, and in severe cases, air motion may be significantly impaired that wheezing cannot be heard.
Signs which occur during an asthma attack include the use of accessory muscles of respiration (neck muscles), there may be a paradoxical pulse (a pulse that is weaker during inhalation and stronger during exhalation), and over-inflation of the chest. Skin and nails may also turn a blue color from lack of oxygen.
Status asthmaticus is an acute exacerbation of asthma that does not respond to standard treatments of bronchodilators and steroids. Using nonselective beta blockers with status asthmaticus can be fatal.
Asthma is common among top athletes. There appears to be a relatively high incidence of asthma in sports such as cycling, mountain biking, and long-distance running, and a relatively lower incidence in weightlifting and diving. It is unclear how much of these disparities are from the effects of training in the sport.
Exercise induced asthma can be treated with the use of a short-acting beta2 agonist.
Asthma is commonly diagnosed as a result of (or worsened by) workplace exposures. Still most cases of occupational asthma are not reported or are not recognized as such. Estimates suggest that 15–23% of new-onset asthma cases in adults are work related. Most cases are associated with the manufacturing and services industries. Animal proteins, enzymes, flour, natural rubber latex, and certain reactive chemicals are commonly associated with work-related asthma. When recognized, these hazards can be mitigated, reducing the risk of disease.
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