Asthma 

part from respiratory infections, climatic factors, and air pollution caused by modern progress, immunological problems can explain some of the increase in asthma in recent years. It has been found that the IgE concentration of asthma patients is higher than normal, and there is a strong affinity between IgE and adipose and basophil cells. IgE can bind to IgE receptors in the cell membrane, and the binding of two specific IgE antibodies and antigens can induce basophils and adipose cells to release histamine and other mediators, initiating a series of reactions in the target organs. These reactions, which are the symptoms of asthma and other allergies, include smooth muscle spasms in the bronchi, dilation and congestion of the blood vessels, increased osmotic pressure of the capillaries, increased secretion from mucous glands, and stimulation of peripheral nerves. The affected cells also release chemotactic factors, inducing a chain reaction resulting in inflammation. 

      Among the things that may trigger asthma attacks are changes in the weather, respiratory  infections, cool morning air, dust, microbes in the air, animal dander, air pollution, exhaust gasses, and certain foods. Apart from taking necessary drugs or receiving allergy therapy in accordance with their physicians' instructions, asthma patients should avoid contact with allergens and, even more importantly, should strengthen their immunity. 

Reference: Chin Kang-ling; 1991; Asthma-type Allergies and Immunotherapy: Tzu Chi Medicine, 3: 82-84.