求翻译：　　（2）常在夜间或清晨突然发作，可有先兆症状，如咳嗽、胸闷、鼻痒等，随之呼吸困难，严重者可有紫绀，大量冷汗，咳嗽明显，初为干咳，合并感染时可咳出粘稠痰液。是什么意思？

(2) often a sudden onset at night or early morning, may have aura symptoms such as cough, chest tightness, nasal itching, etc., along with breathing difficulties, severe cases may have cyanosis, a lot of sweat, cough clear, first as a dry cough, infection can coughed up thick sputum.

正在翻译，请等待...

　　(2), often at night or early morning seizure, aura symptoms such as coughing, chest tightness, nasal itching and so on, along with breathing difficulties, and in severe cases cyanosis, a large number of cold sweat, coughing obvious, beginning as a dry cough, infection may cough with thick sputum.