Thanks for your question. Common cold causes increased secretions in the posterior part of nose called post nasal drip which may cause severe cough. Also any upper respiratory tract infection causes mucosal swelling & increased sensitivity to inhaled cold air , which may also cause constant cough. If you feel something is there in your throat , it may also be due to a condition called chronic pharyngitis. Cough suppressants taken as per physicians advice usually work well in these conditions. Please see an ENT physician for diagnosis and management.