In recent years, we have found in our clinical practice that the incidence of chronic cough is increasing, and that conventional anti-inflammatory, cough suppressant and phlegm treatment is often not very effective, and the patients themselves lack sufficient attention to the symptoms of cough, causing repeated delays and aggravation of the condition. The cough improves quickly after treatment. Cough as a symptom is very common, but we are talking about chronic cough, which is short for chronic cough of unknown origin and has a specific definition: a person with cough as the only or main symptom for more than 8 weeks and no significant abnormalities on chest X-ray is called chronic cough. There are many different causes of chronic cough, not only related to the respiratory system, but also to the nasopharynx and the digestive system. Among them, the common causes are postnasal drip syndrome, cough variant asthma and gastroesophageal reflux. This is in line with the Chinese medical classic Huangdi Neijing, which states that “all five internal organs and six internal organs cause coughing, not only the lungs”. Here we will introduce the common causes and characteristics of chronic cough. According to the structure of the respiratory tract, let’s look at which diseases can cause chronic cough from top to bottom: First, the nose: the cough caused by nose lesions is postnasal drip syndrome, which can now be classified as upper airway cough syndrome. Allergic rhinitis, sinusitis, and non-allergic rhinitis can all cause this condition. Characteristics of cough caused by nasopharynx: 1. Coughing is predominant during the day, and less often waking up with a cough after going to sleep; 2. Nasal snot flows from the back of the nose into the mouth, the feeling of mucus adhesion on the back wall of the pharynx, and patients often need to clear their throat, which can be accompanied by symptoms of nasal congestion, runny nose and itchy throat; 3. The condition of the nasopharynx can be checked by yourself in the mirror: mucus adhesion on the back wall of the pharynx, cobblestone-like appearance Once a friend with a cough finds his symptoms meet the characteristics just listed, it is recommended that you go to the ENT department for a specialist examination. Looking down from the nasopharynx, the trachea in front and the esophagus in the back, both of which run parallel downward, gastroesophageal reflux can also cause a lingering cough Gastroesophageal reflux is an invisible killer that causes chronic cough and even asthma. This disorder is the reflux of stomach acid and other stomach contents, the main digestive juices in the stomach, into the esophagus, which causes coughing. Characteristics of gastroesophageal-related cough 1. The onset of cough is clearly associated with eating, such as coughing after meals, coughing after eating, or coughing induced by acid reflux at night; 2. It is often accompanied by acid reflux, belching, burning sensation behind the sternum, and bitterness in the mouth If your cough is accompanied by these gastrointestinal symptoms, it is recommended that you visit a gastroenterologist for 24-hour monitoring of esophageal pH to make a diagnosis. If there is no condition for esophageal pH monitoring, diagnostic treatment with the antacid drug Loxac and gastrointestinal motility drugs, such as morpholine, can be used. The main respiratory cause of chronic cough is cough variant asthma. When asthma is mentioned, people often think that wheezing, croup, and chest suffocation are the only asthma, and it is difficult to associate simple cough with asthma. In fact, cough variant asthma is a special type of asthma in which cough is the main or only clinical manifestation without obvious symptoms such as wheezing and shortness of breath. cough characteristics of cough variant asthma: irritating dry cough, no sputum It is more common at night or early in the morning. Irritating odors such as cold air, dust and oil smoke can trigger or aggravate the cough. The airway hyperresponsiveness test is positive. In addition, patients who usually suffer from allergic rhinitis must be further examined to exclude cough variant asthma once they develop a chronic cough. This is because several studies have shown that at least 60% of patients with perennial allergic rhinitis have occult bronchial asthma or have developed asthma.