Hello Welcome in H.C.M. I have gone through your query regarding cause of sore throat, cough and congestion in nose. Involvement of nose and throat as you are having is consider as upper respiratory tract. As for as congestion of nose is concerned it is by infection in nose and paranasal sinuses, infection may be bacterial or viral. Beside this allergy is also responsible for congestion in nose, paranasal sinuses and throat. Whenever nose and sinuses are inflammed there develops post nasal drip whichcarres infection to throat secondarly throat may also be involve in direct infection from oral cavity. Most of the time the infective agent remains same in nose, sinuses and throat, it may be bacterial, viral or allergic. Since you are having upper respiratory tract infection for last 12 days so it will be better to consult an ENT doctor for physical examination, relevent investigations and accordingly treatment planing. Till you are in waiting for specialist you may take- 1- Tab Paracetamol. 2- Anti histaminic. 3- Decongestant. 4- Steam inhalation / warm saline gargling. 5- Antibiotic (preferably broad spectrum). Probably you got the reply of your query. Regards.