when body has energy to repair, it looks to be sick

But after repair done, body would be better. And certain period after, body collect more energy, then begin to anthoer repair cycle, then you would look like to be sick again.

I had that experience when I back to China 'yang bin', it really was 'yang' sick.

The same for a lot of busy people, when they take a break, one week or so vacation, they would be sick.