I feel very bad. 我感觉不太舒服。

Shall I call a doctor for you? 要我帮您叫医生吗?

I'm sorry to hear that you are not feeling well. What's the problem? 听说您不舒服，我很难过，您哪里不舒服?

Have you had any fever or any other symptom such as a sore throat or a cough? 您有发烧或其他如嗓子痛、咳嗽之类的症状吗?