The first thing you should do when you have a cold that has been bad for more than ten days is to check your blood count and see if there are any elevated white blood cells in the blood count. If the white blood cells are elevated, it means that the cold is caused by bacterial infection. The use of cold drugs alone is not effective enough, so there will be a cold more than ten days bad phenomenon. You can take oral antibiotics for treatment, penicillin if there is no allergy, you can use amoxicillin clavulanate potassium. If there is an allergy, you can use cephalosporin antibiotics, such as cefixime, cefradine. Another cause could be a cold that leads to a lower respiratory tract infection, which can also occur when the cold is not good for more than ten days. A CT chest examination can often confirm the diagnosis, and hospitalization for intravenous antibiotic therapy is required if necessary.