Chronic cough, sputum, and wheezing in winter and spring have an acute or delayed onset and are mostly preceded by a mild upper respiratory tract infection. However, the cause of onset is determined by the specific clinical manifestations. Many people have a persistent cough in the cold winter months, so what are the causes of chronic cough, sputum and wheezing in winter and spring? 1. Cold Most winter coughs are the pre-cold, accompanying symptoms or sequelae of a cold. In addition, other symptoms such as runny nose, nasal congestion, sore throat, headache and dizziness may occur in winter colds. When the cold is cured, the coughing symptoms will gradually disappear. 2. Inflammation of the respiratory tract Inflammation of the respiratory tract is an important cause of winter cough. When various pathogens invade the respiratory tract and cause infections of the nasopharynx, tonsils, trachea, bronchi and even the lungs, pharyngitis, tonsillitis, tracheitis, bronchitis, pneumonia and other inflammatory diseases occur. 3. Allergies Allergic cough is also one of the causes of winter cough, such as contact with allergens such as pollen, dust mites, dust, animal dander, chemicals, etc. In particular, people with allergies will have recurrent cough attacks with little sputum and no clinical manifestations of infection. Therefore, avoiding allergens in general can alleviate cough symptoms. 4. Cold air Coughing in winter is also related to cold air. People who are sensitive to cold air, for example, are easily stimulated to cause coughing, so it is best to go out less in colder weather, such as wearing a mask as much as possible when going out, and pay attention to keeping warm. 5. Foreign bodies in the respiratory tract If you have a recurrent, persistent cough in winter, it may be caused by some small foreign bodies in the trachea or tuberculosis. When the mucous membrane of the respiratory tract is stimulated by a foreign body, it can cause a cough, so it is best to go to the hospital for consultation and timely treatment. Many interstitial lung diseases often have a dry cough as the main symptom in the early stage, in which case pulmonary function tests can help with early detection; drug-induced cough is commonly caused by ACEI and beta-blockers, with an incidence of about 15%. It occurs 24 hours or months after drug administration, more in women than men, and may be related to increased sensitivity of cough receptors. It resolves after several days to 4 weeks of drug discontinuation; after excluding these factors, psychogenic cough can be considered and is associated with negative emotions such as stress, anxiety, and sadness. It is characterized by a barking or goose cough, an irritating dry cough, often accompanied by clear throat sounds. The cough is not associated with food or water intake. Infectious cough can gradually evolve into a psychogenic cough.