Asthma | |
---|---|
Peak flow meters are used to measure the peak expiratory flow rate, important in both monitoring and diagnosing asthma. | |
Specialty | Pulmonology |
Symptoms | Recurring episodes of wheezing, coughing, chest tightness, shortness of breath |
Duration | Long term |
Causes | Genetic and environmental factors |
Risk factors | Air pollution, allergens |
Diagnostic method | Based on symptoms, response to therapy, spirometry |
Treatment | Avoiding triggers, inhaled corticosteroids, salbutamol |
Frequency | 358 million (2015) |
Deaths | 397,100 (2015) |
Classification | |
---|---|
External resources |
Asthma is a common long-term inflammatory disease of the airways of the lungs. It is characterized by variable and recurring symptoms, reversible airflow obstruction, and bronchospasm. Symptoms include episodes of wheezing, coughing, chest tightness, and shortness of breath. These episodes may occur a few times a day or a few times per week. Depending on the person, they may become worse at night or with exercise.
Asthma is thought to be caused by a combination of genetic and environmental factors. Environmental factors include exposure to air pollution and allergens. Other potential triggers include medications such as aspirin and beta blockers. Diagnosis is usually based on the pattern of symptoms, response to therapy over time, and spirometry. Asthma is classified according to the frequency of symptoms, forced expiratory volume in one second (FEV1), and peak expiratory flow rate. It may also be classified as atopic or non-atopic, where atopy refers to a predisposition toward developing a type 1 hypersensitivity reaction.
There is no cure for asthma. Symptoms can be prevented by avoiding triggers, such as allergens and irritants, and by the use of inhaled corticosteroids.Long-acting beta agonists (LABA) or antileukotriene agents may be used in addition to inhaled corticosteroids if asthma symptoms remain uncontrolled. Treatment of rapidly worsening symptoms is usually with an inhaled short-acting beta-2 agonist such as salbutamol and corticosteroids taken by mouth. In very severe cases, intravenous corticosteroids, magnesium sulfate, and hospitalization may be required.