Many people experience a cough, and some may not think about it. Coughing is a protective reflex of the body, but it is also a pathological symptom. Don’t think that coughing twice is a trivial matter. Many people cough for two months and still can’t stop, and some of these coughs are caused by inappropriate medical treatment. Severe coughing, especially intense and frequent dry coughing, can affect sleep and rest, and even lead to complications in several systems, including cardiovascular, gastrointestinal, and respiratory. Common complications include feeling unwell, fatigue and weakness, sleeplessness at night, muscle aches, hoarseness and urinary incontinence. The medical community classifies coughs according to their duration into acute, subacute and chronic coughs. A cough lasting less than 3 weeks is usually referred to as an acute cough, a cough lasting between 3 and 8 weeks is defined as a subacute cough, and a cough greater than or equal to 8 weeks is considered chronic. It is relatively easy to diagnose the cause of acute cough. The common cold is the most common cause and is treated symptomatically, usually with anti-allergic drugs and decongestants. It is self-limiting and usually resolves within 2 weeks. Subacute cough is mainly seen after acute upper respiratory tract infections, especially colds, where some of the symptoms of the cold itself disappear but the cough persists for a period of time, clinically known as post-cold cough. This type of cough usually resolves on its own, or can be treated with cough suppressants and anti-allergy medications for a short period of time in patients who have had it for a long time. The etiology of chronic cough is more complex, involving not only the respiratory system, but also some diseases of the ear, nose and throat and digestive system. Because chronic cough patients have few accompanying symptoms and little abnormality on Χ-ray examination, the misdiagnosis rate is quite high. As a result of misdiagnosis, these patients are treated with a large number of antibiotics, and some patients also undergo repeated Χ-ray chest films, CT and fibrinoscopy due to unclear diagnosis, which not only increases the financial burden of the patient, but also greatly affects the patient’s life, study and work. If chronic cough of unknown origin is clearly diagnosed and treated for its cause, the majority of patients can achieve significant treatment results. There are four main causes of this type of cough: cough variant asthma, postnasal drip syndrome, eosinophilic bronchitis and gastroesophageal reflux cough. In cough variant asthma, only the symptoms of cough without wheezing are manifested. Patients with a long-standing cough that does not respond well to common anti-inflammatory therapy; or recurrent attacks that are not easily cured; or a cough that is distinctly seasonal and intensifies in the morning or into the night. Cough can be induced by general irritation, such as cold wind or oil and smoke irritation. If any of these conditions are present, cough variant asthma cannot be excluded. Appropriate pulmonary function tests (e.g., bronchial excitation test, diurnal peak flow rate monitoring) should be performed to confirm the diagnosis. Eosinophilic bronchitis with daytime or nighttime cough, usually dry and sensitive to fumes, dust, odors or cold air. Sputum eosinophils are elevated, lung ventilation is normal, there is no airway hyperresponsiveness, and glucocorticoid therapy is effective. In postnasal drip syndrome, the cough is mainly caused by backflow of nasal secretions from nasal diseases into the postnasal and pharyngeal areas, or even into the airway, stimulating the cough receptors in these areas. The cough caused by postnasal drip syndrome occurs mainly during the daytime and less frequently after sleep, and may include symptoms such as flu drip in the throat, a feeling of mucus adhesion in the oropharynx, frequent throat clearing, throat itching or nasal itching, nasal congestion, runny nose, and sneezing. These symptoms are not specific and need to be combined with clinical history, physical signs, ancillary examinations and treatment response to make a comprehensive judgment. Most patients produce efficacy within a few days to 2 weeks after treatment. GERD cough, with a predominantly daytime cough with heartburn and reflux, may also present as belching, nausea, epigastric pain or retrosternal pain. Esophageal pH monitoring is the best monitoring method available, but the final diagnosis needs to be based on the effectiveness of anti-reflux treatment. Therefore, when a cough appears we should pay attention to the nature of the cough, such as the urgency of its onset, duration, season of onset, severity, relationship to body position, exertion, eating, presence of triggers, and accompanying symptoms, in order to diagnose it as soon as possible and receive timely treatment. Although many of the medications used to treat cough are over-the-counter, it is important to identify the cause of the cough to treat chronic cough, and you should never just buy a little cough medicine to deal with it yourself. When a cough has been present for more than three weeks, do not blindly take antibiotics and cough suppressants on your own, but go to the respiratory clinic of a regular hospital so that the cause can be detected and treated early. Only when the cause of chronic cough is clearly diagnosed and the treatment is tailored to the cause can the treatment be effective.