Philippa says

aCommon colds take up to two weeks to get better. Sore throats take seven to eight days, sinusitis two to three weeks and ear infections about eight days. Coughs can go on a bit longer – up to three weeks, though if you have a cough that lasts longer, please visit your doctor to rule out anything suspect. If you do have one of these illnesses, make sure you drink plenty of fluids to stay hydrated (and soothe a sore throat), use over-thecounter medication if needed and seek advice if you are concerned.