哮喘突然发作,常常是有诱因的,如接触花粉等过敏源、感染、运动、冷热刺激等。发作前,病人常会有鼻子、眼睑发痒,连续打喷嚏、流鼻涕等先兆症状,病人或家人发现后,应提前用药,防止突然发作。若哮喘发作,应尽快缓解气道狭窄。身边的亲友应协助病人取坐位或半坐位休息,下肢下垂,切忌平卧。因为平卧会增加肺淤血及心脏负担,使哮喘加重。接着,应协助病人吸入家中备用的喷雾剂。另外,要帮助病人保暖,保持环境 Sudden onset of asthma, often have incentives, such as exposure to pollen and other allergens, infections, exercise, hot and cold stimulation. Before the attack, patients often have nose, itchy eyelids, continuous sneezing, runny nose and other aura symptoms, the patient or family found that after the medication should be used in advance to prevent a sudden attack. If asthma attacks, should be as soon as possible to ease airway stenosis. Friends and relatives around should help patients take a seat or half-sitting rest, lower limbs sagging, avoid supine. Because lying will increase lung congestion and heart burden, asthma worse. Then, patients should be assisted inhalation of spare sprays at home. In addition, to help patients keep warm and maintain the environment