Coughing is a natural reflex for clearing the throat and lungs of irritants. An occasional dry cough is rarely a cause for concern, but persistent coughing can indicate an underlying medical condition that may be more serious. Do you have any other signs or symptoms such as fever, fatigue? And have you been taking some medications, such as ACE-inhibitor drugs for high blood pressure? The treatment depends on the causes. You are suggested to see a doctor for diagnosis.