How long have you been having the pains? 你这样痛多久了？
How long have you been...?
How long have you been learning English?
How long have you been in China?
How long have you been feeling like this?
A:Hello,what's wrong with you?
B:I'm afraid there might be something wrong with my stomach.It is so painful.
A:How long have you been having the pains?
B:Since last night.And it seems to be worse this morning.
A:So what kind of pain do you feel?Are they sharp pains or burning pains.
B:Ur...I think they are burning pains.
A:Did you vomit?
B:Yes,I did.And I have been filled with nausea.
A:Did you have a fever?
B:I'm not sure because I didn't take my temperature.
A:I get it.Please lie on the bed and let me examine you.