*4.3.1 Time of early signs and symptoms occurrence*

Most AECOPD patients cannot tell the specific time of early signs and symptoms of exacerbations occurrence. They can be appeared at any time. However, there are some COPD patients who can identify the time of early warning signs and symptoms usually occurring: (1) morning, (2) evening, and (3) night. AECOPD can happen any time. Some patients have signs and symptoms in the morning or/and in the evening or/and in the night or all the day. It occurs different individually.
