Analysis of illness: Hello, stewed Sydney with rock sugar is generally used for hot cough, not for cold cough, and it is best to make sure that it is the kind of cough for re-treatment. Suggestion: Cough is a common minor illness. When we catch a cold, catch a cold, have a dry climate or are allergic to something, we may cause cough. We don't need to take medicine for the cough caused by these situations.