Asthma is a lung disorder in which there is intermittent inflammation and narrowing of the airways in the lungs. People with asthma have recurrent attacks when the muscles in the walls of the airways contract, causing narrowing.
This is usually in response to an allergen, such as pollen, house dust mites, or pet dander (minute scales from animal hair, feathers, and skin), but an attack may also be triggered by factors such as inhaled chemicals, irritants, or dusts; certain medications; stress; exercise; or respiratory infections.
An asthma attack causes the sudden onset of wheezing, shortness of breath, tightness of the chest, and coughing. In a severe attack, breathlessness may be so bad that speaking is impossible; the lips, fingers, and toes may turn blue; and the person may become unconscious. Asthma is treated with medication to prevent or relieve attacks.
A severe attack requires urgent medical help
