A chronic cough is a cough that lasts for more than three weeks. Chronic coughs are not considered a disease, rather a symptom of another disorder. Coughs are caused because of an irritant; these irritants can be from a chemical, mucus, stomach acid or particles in the air such as dust. These irritants will stimulate the nerves in the respiratory tract causing you to cough.
Postnasal drip is one of the most common causes of a chronic cough. Glands in your throat, nose and sinuses create mucus, mucus helps aid in keep the nasal passages clean and moisturized. Commonly these fluids are swallowed without being aware but when one suffers from an accumulation of increased fluids in the back of the throat the reaction is a cough. Increased mucus can be caused by sinus infections, colds and allergies.
Gastroesophageal reflux disease (GERD) is stomach condition where the acid flows from the stomach up the esophagus to the throat. Due to the constant irritation to the throat and esophagus and sometimes the lungs this condition can produce chronic coughing. When GERD is properly treated by diet or medications and the acid is kept from flowing up the esophagus chronic cough disorders will disappear.
Asthma is a disease that affects the airways causing difficulty in breathing or the sound of wheezing while breathing. One of the symptoms of asthmas sufferers is a chronic cough. Hyperactive airways disease is a type of asthma where a chronic cough is the only symptom. These types of coughs can be triggered by chemicals, exposure to cold air and fragrances.
Angiotension-converting enzyme inhibitors also know as ACE inhibitors commonly used to treat high blood pressure and heart failure can cause a chronic cough. The chronic cough usually goes away once the medication has been discontinued.
Chronic bronchitis causes inflammation to the bronchial tubes which can cause a chronic cough that brings up discolored mucus. Chronic bronchitis is commonly suffered by people who are former or current smokers. Chronic cough symptoms are usually a sign that damaged as occurred to the airways or the lungs.
Medicine Net: Chronic Cough
Pulmonology Channel: Chronic Cough Causes