Asthma is a chronic disorder, of the tubes that transport air to lungs called airway. Usually the airways are hyperactive i.e. they react in an exaggerated way to the known allergens, as they get irritated and inflamed the airways narrow down reducing the influx of air and precipitating the symptoms.

Other allergic conditions, such as eczema (atopic dermatitis), hay fever (allergic rhinitis), and food allergies, the prevalence of asthma appears to be on the rise. The most important cause is the interaction between the genetic factors and the environmental factors. This usually presents with shortness of breath, chest tightness, coughing and wheezing are the cardinal signs, but the only signs.

It can occur in children it is usually brought out by some allergens, mostly animal danders; while the adult-onset asthma is most common which usually occurs following an upper respiratory infections, due to respiratory syncytial virus. Asthma is usually diagnosed by respiratory function tests or allergen test. Asthma is treated with two kinds of medicines: quick-relief medicines to stop asthma symptoms and long-term control medicines to prevent symptoms.