When you have a high fever or stomach ache, you think about whether you are sick or not, and you rush to the doctor for injections and medication. But when it comes to cough, many people don’t take it seriously at all. Coughing? Leaders have to cough loudly and clearly before giving a report, which is considered a disease? It is not known that a small cough may be a precursor to a disease, and the outcome can be very different if you do not investigate and treat it. Among the various symptoms of the respiratory system, the most easily overlooked is cough, especially chronic cough. Coughing is not a disease in itself, it is a self-protection for the body to expel foreign bodies from the respiratory tract, but it is often a “sign” of a hidden illness. Nine times out of ten, chronic cough has a clear cause, and if the patient is seen in a timely manner, the doctor can trace it back to its source, like a detective solving a case, and find the lesion lurking in the patient’s body. There is a medical saying that “the same disease has different symptoms and different diseases have the same symptoms”, which means that the same disease may have different clinical manifestations, while different diseases may also show the same symptoms. The causes of cough, for example, vary widely. The most common cause of cough is microbial infection. These include common bacteria, atopic Mycobacterium tuberculosis, viruses, fungi, and others such as lung flukes, roundworms, tapeworms, etc. Autoimmune diseases, including asthma, allergic alveolitis, etc. Some of these diseases are triggered by exogenous irritants, such as pollen and seeds from plants in spring or pet hair and secretions, which may also cause coughing once they invade the lungs. Heart disease, such as heart failure or pericardial disease, can also cause coughing symptoms. The purpose of analyzing and identifying the cause of the cough is still to treat it. Therefore, if you have a cough, especially a chronic cough of more than two weeks, you should not just drink some cough drops or ignore it. The first step is to review your medical history with your doctor. For example, any history of heart disease, tumors, systemic lupus erythematosus or rheumatoid arthritis, immune deficiency due to chemotherapy for tumors, organ transplants, etc., exposure to pollen, seeds, pets or old dust, and high blood pressure medication. As the saying goes, to catch the thief first, find the “culprit”, targeted treatment, you can achieve the best results. Microbial infections can be treated with various anti-inflammatory, antiviral and antifungal treatments; heart disease or rheumatoid arthritis should be treated first; coughs caused by dust and pets can be almost eliminated as long as the allergens are kept away.