发作

老爷爷患有多年季节性慢性哮喘病，深秋天气骤冷时很容易发作，出门必须格外注意保暖。

lǎo yé yé huàn yǒu duō nián jì jié xìng màn xìng xiāo chuǎn bìng, shēn qiū tiān qì zhòu lěng shí hěn róng yì fā zuò, chū mén bì xū gé wài zhù yì bǎo nuǎn.

My grandfather has been suffering from seasonal chronic asthma for many years. It is easy to have an attack when the weather suddenly gets cold in late autumn. He must pay special attention to keep warm when going out.