This evening I was with some Chinese friends, one of whom told me has not been well the past two days. Assuming she may not be comfortable to talk about her illness with me ( as it's confidential) I didn't ask what was  wrong with her. However, I found myself asking her if she had taken any medication for her illness. She told me she had but was quick to warn me never to ask a Chinese in the morning if they have taken medication or not. She continued to say it's ok to ask such a question any time after lunch ( Of course she assured me there was nothing wrong with my question but simply wanted to advise me against asking that kind of question in the morning). I was gripped with some strange feeling.

I asked for an explanation  for this. She hesitated to respond. Then one Chinese guy who was with us simply  told me it's difficult to explain. My female friend, who was unwell,  nodded in agreement. I didn't insist on getting an explanation as the atmosphere, at least from how I read it,  made me feel I  could easily step into a no-go-zone according to Chinese culture by asking further, which would obviously offend them, I reasoned.

I therefore would like to ask those familiar with Chinese culture regarding this kind of thing. Why is it wrong to ask in the morning if a Chinese friend who is unwell has taken medication or not?  Note: emphasis was on asking in the morning. The friends I was with told me it's ok to ask this kind of question any time after lunch. Please help!