Wu yanbing
In autumn, the climate is dry and the temperature is low, so all kinds of discomfort symptoms of respiratory tract always love to make trouble in this season. Many people have this feeling. In autumn, their throats are like they can’t be pulled open. They are hot, dry and itchy, and have a lot of phlegm. If they are not careful, they will be harassed by coughing, which will be annoying. Today, let’s talk about why the respiratory tract is fragile in autumn and who is prone to cough.
Cough is not necessarily a bad thing.
The respiratory tract is divided into upper respiratory tract and lower respiratory tract. The upper respiratory tract includes mouth, nose, pharyngeal cavity and throat, and the lower respiratory tract consists of trachea, bronchus and lung. Respiratory tract is the internal organ that people have the most contact with the outside world every day, and it is vulnerable to various external stimuli, such as cold, heat, dryness and infection. However, the lung is a relatively "cute" organ. It does not feel hot or cold, pain or touch. Frankly speaking, it has no feeling, and the biggest response to injury is coughing.
When the airway is stimulated, the nerve reflex will make the human body produce a series of actions: the glottis are closed, and the breathing muscles contract rapidly to produce exhalation; Because the glottis is closed, the breath can’t go out, and the pressure in the chest cavity rises sharply, which in turn pushes the glottis open; Then, the gas is ejected at high speed, taking out the "bad" things in the trachea — — This is the protective defense mechanism of the lung.
Therefore, coughing is not necessarily "sick", and coughing when sick is not necessarily a bad thing. Cough can help people expel germs from the body, which is conducive to the improvement of their condition.
Of course, coughing is very annoying. Cough during the day; Cough at night; Talk too much and cough; Cough when inhaling cold air; Especially when coughing violently in public, not only the patient feels uncomfortable, but also others feel nervous. When some people cough violently, they will retch, affect their sleep, and even have pneumothorax. If the pleura on the lung surface ruptures, they will also have chest pain and hold their breath, which will be life-threatening in severe cases. Some patients with severe cough can lead to loss of consciousness, which is called "cough syncope" in medicine. This situation is very dangerous when driving or working at high altitude. Therefore, patients with relevant medical history should go to the hospital as soon as possible for symptomatic treatment.
According to the duration, there are three situations.
When it comes to coughing, we must first distinguish whether it is a real cough. Some people call the action similar to "clearing throat" cough, usually one or two times, because they feel uncomfortable in the throat or something sticks; Some coughs are habitual actions, which are common in smokers and are mostly caused by pharyngitis. What is really a cough is mostly manifested as a series of coughs one after another.
In medicine, cough is divided into acute cough, subacute cough and chronic cough according to the length of cough time.
1. Acute cough refers to cough within 3 weeks, mostly cough after infection, which is caused by diseases such as colds and tracheitis;
2. Subacute cough refers to cough from 3 weeks to 8 weeks. In addition, this situation occurs in older patients, mainly due to post-infection cough;
3. Chronic cough refers to cough with a course of more than 8 weeks. The main causes are cough variant asthma, postnasal drip syndrome (upper airway cough syndrome), eosinophilic bronchitis, gastroesophageal reflux cough and allergic cough.
Seasonal cough is mostly caused by these conditions.
Cough can appear all the year round, but it happens frequently when the season changes. Because the alternation of cold and hot is obvious when changing seasons, especially in autumn, many people do not pay attention to adding clothes and keeping warm in time, and their immunity is reduced, which will create opportunities for all kinds of bacteria and viruses to invade the human body, and then respiratory tract bacterial or viral infection will occur, and the incidence of cough after infection is higher, and respiratory tract infection is easy to induce cough variant asthma. This is also the main reason why everyone feels that it is easy to cough in autumn.
Why do you cough after respiratory tract infection? In fact, post-infection cough is a respiratory symptom caused by airway inflammation repair. After the infection improves, it will be cured by simply using antitussive drugs, and the course of disease is relatively short.
The essence of cough variant asthma is the increase of airway sensitivity caused by chronic airway inflammation, which is non-infectious and can be induced by respiratory infection without taking anti-inflammatory drugs. It may or may not be allergic. Although it is called "asthma", the patient has no breathing and his lung function is normal. However, some patients can turn into typical asthma. Therefore, correct treatment can reduce the incidence of typical asthma.
The dry and cold climate is very unfriendly to the airway, and the cold itself is a kind of stimulation, while the low temperature reduces the water content in the air, which makes the airway more sensitive when it is short of water, thus leading to cough and wheezing. Nasal cavity can warm and humidify inhaled air, but too dry, breathing with open mouth and strenuous exercise may reduce airway humidity and increase airway sensitivity.
In addition, there are allergic factors. In addition to spring, pollen allergy in autumn is also very serious, and both spring and autumn are the seasons prone to allergic cough, allergic rhinitis and asthma.
It should be reminded that cough variant asthma, postnasal drip syndrome, eosinophilic bronchitis and allergic cough are all related to allergies to some extent. If there are symptoms such as sneezing, runny nose, itchy eyes and nose, and watery eyes while coughing, it will be very effective to receive antiallergic treatment if you go to the hospital to find out that eosinophils are high and total IgE (immunoglobulin E) is high.
Why do diagnostic tests often choose CT?
Theoretically, lung CT is not a necessary examination to see cough. In most cases, the lung CT findings of patients with simple cough are normal. Most chronic coughs, such as cough variant asthma, eosinophilic tracheitis, allergic cough, etc., have no obvious lesions in the lungs. Then why do doctors often recommend lung CT examination when they go to the hospital to see a cough?
Because doctors must first rule out some serious diseases, such as tuberculosis, lung cancer, bronchiectasis and so on. The treatment of these diseases is mainly to treat the primary disease, not to treat cough alone. Doctors should first see if there is any disease in the lungs, and the best way to "see" the lungs is lung CT and X-ray chest film.
Which is clearer, lung CT or X-ray chest film? Lung CT is relatively clear, X-ray chest film will produce many artifacts, and heart blood vessels and bones may also block the focus, so bronchiectasis and lung cancer are mostly diagnosed by lung CT, while infectious diseases such as tuberculosis and pneumonia can be diagnosed according to X-ray chest film.
The attending doctor usually asks the patient’s medical history in detail, initially judges the nature of cough and considers what examination to do. For the elderly, patients with chronic cough and hemoptysis, lung CT examination is the first choice. Because the X-ray absorbed dose of lung CT examination is higher than that of chest X-ray film, it is suggested that patients should take the recent imaging results with them when they go to different hospitals one after another to avoid repeated examination.
Do I have to take medicine for coughing?
Many old people give medicine to their children when they cough, saying, "I want to suppress the disease"; Some patients are afraid of tracheitis, and then turn into chronic cough, and take medicine as soon as cough appears. But as long as it is medicine, there are side effects, especially for children. Therefore, if you don’t have a severe cough, don’t take cough medicine in a hurry, but see a doctor in time to take medicine for the cause.
For patients with cough, the doctor’s primary concern is whether there is respiratory infection. If there is a severe cough, the stimulation of the airway may aggravate the inflammatory reaction and delay the improvement of the condition. This situation requires symptomatic medication. Let’s talk about what drugs may be used for cough.
● antitussive drugs
Antitussive drugs work quickly, but they don’t target the cause. Commonly used antitussive drugs mainly include compound methoxyphenamine, licorice tablets, dextromethorphan, compound codeine syrup, traditional Chinese medicine pulmonary cough, loquat syrup, etc., which can achieve antitussive purpose by inhibiting central and peripheral cough reflex, antiallergic, bronchiectasis and other mechanisms. Among them, compound methoxyphenamine is mostly used to treat acute and chronic cough, and compound dextromethorphan solution is often used to treat cough after a cold.
Most western medicine antitussive drugs are compound preparations, which may include antitussive, chlorpheniramine, pseudoephedrine, etc., with relatively more side effects, but little impact, so you can take them with confidence. Taking chlorpheniramine will cause drowsiness, which is not suitable for professionals who need to concentrate on their work, such as drivers. You can change other antitussive drugs according to your doctor’s advice.
It should be noted that most western medicine compound antitussive drugs have the same ingredients or substitute ingredients, so do not take them at the same time.
● Antiallergic drugs
Commonly used antiallergic drugs include loratadine and cetirizine, which are suitable for cough caused by allergic factors, especially for patients with allergic rhinitis.
Among them, montelukast is a relatively safe drug for treating asthma and allergic rhinitis, and can be used simultaneously with other antiallergic drugs.
In addition, among inhaled hormones and bronchodilators, salmeterol and fluticasone, budesonide and formoterol are commonly used to treat cough variant asthma, eosinophilic tracheitis, allergic cough, etc., which can reduce the probability of patients developing typical asthma while relieving cough.
Many patients are worried about the side effects when they hear hormones. In fact, these drugs have been on the market for a long time, and the incidence of serious side effects observed is very low, which is relatively safe. It is important to gargle in time after inhalation to remove the excess drugs in the mouth.
Low acid inhibitor
Include omeprazole and lansoprazole, which can inhibit gastric acid secretion, and is mainly used for gastroesophageal reflux cough.
● Antibiotics
Including cephalosporins, azithromycin, etc., mainly used for cough caused by infection.
Low expectorant drugs
Including eucalyptus, acetylcysteine capsules, ambroxol hydrochloride, fresh bamboo juice, etc., which can dilute sputum, and sputum is not easy to cough up and is suitable for postnasal drip syndrome. However, routine use is not recommended for dry cough.
Health tips
How to distinguish "COVID-19" cough from common cough?
Now China is making every effort to prevent and control the COVID-19 epidemic. When it comes to "cough", it will inevitably make people nervous. So, what’s the difference between a cough caused by Covid-19 and a cough caused by a common respiratory infection?
In view of the complexity of symptoms caused by Covid-19, it is impossible for patients to screen for infection by themselves. Clinically, in addition to fever, Covid-19 infection can sometimes be characterized by simple cough (mostly without sputum), which can also be the only first symptom of COVID-19 patients.
Therefore, if you have a cough, you should pay attention to the symptoms of cough and go to a regular hospital in time if you have a history of epidemiological contact. At this time, don’t buy or take medicine by yourself, so as not to delay the diagnosis of the disease and cause the spread of the virus.
(Author: Beijing Chaoyang Hospital, Beijing Institute of Respiratory Diseases)