What Causes a Cough?

Cough is a common respiratory tract symptom. It is caused by inflammation, foreign body, physical or chemical irritation of the trachea, bronchial mucosa or pleura. The performance is firstly the glottal closure, respiratory muscle contraction, increased intrapulmonary pressure, and glottic opening On, air is ejected from the lungs, usually accompanied by sound. Cough has a protective effect on removing foreign bodies and secretions from the respiratory tract. However, if the cough keeps changing from acute to chronic, it often brings great pain to the patient, such as chest tightness, itching, and wheezing. Cough can be accompanied by sputum.

Basic Information

English name: Cough
Visiting department: Respiratory Medicine

Common locations: Respiratory tract
Common causes: Trachea, bronchial mucosa or pleura caused by inflammation, foreign body, physical or chemical irritation

Causes of cough

The formation and recurrence of cough are often the result of a combination of many complex factors.

Inhalation

Inhalation is divided into two types, specific and non-specific. The former are dust mites, pollen, fungi, animal hair debris, etc .; non-specific inhalants such as sulfuric acid, sulfur dioxide, chloramine, etc. Occupational cough specific inhalants such as toluene diisocyanate, phthalic anhydride, ethylenediamine, penicillin, protease, amylase, silk, animal dander or excreta, etc. In addition, non-specific forms of formaldehyde, formic acid Wait.

2. infection

The formation and onset of cough are associated with recurrent respiratory infections. In patients with cough, there may be specific IgE of bacteria, viruses, mycoplasma, etc., and cough can be triggered if the corresponding antigen is inhaled. After virus infection, it can directly damage the respiratory epithelium, resulting in increased respiratory responsiveness. Some scholars believe that interferon and IL-1 produced by viral infection increase the release of histamine from basophils. In the infantile period, there are many people who show symptoms of cough after being infected with respiratory virus (especially respiratory syncytial virus). Cough caused by parasites such as roundworms and hookworms can be seen in areas with poor sanitation.

3. food

Cough attacks caused by dietary relationships are often seen in patients with cough, especially infants are prone to food allergies, but they gradually decrease with age. The most common foods that cause allergies are fish, shrimp, crabs, eggs, milk, etc.

4. Climate change

Cough can be induced when air temperature, temperature, air pressure, and / or ions in the air change, so it is more common in cold seasons or autumn and winter climate changes.

5. Mental factors

Emotional excitement, nervousness, anger, etc. all contribute to cough attacks, which are generally thought to be caused by the cerebral cortex and vagus nerve reflex or excessive ventilation.

6. Sports

70% to 80% of cough patients induce cough after strenuous exercise, which is called exercise-induced cough, or exercise cough. Clinical manifestations include cough, chest tightness, shortness of breath, wheezing, auscultation and wheezing. Although some patients have no typical asthma after exercise, lung function tests before and after exercise can detect bronchospasm.

7. Cough and drugs

Some drugs can cause a cough, such as propranolol, which can cause a cough by blocking 2-adrenergic receptors.

Clinical manifestations of cough

Due to different primary diseases, cough also has different manifestations. May have fever, chest pain, sputum, hemoptysis, sneezing, runny nose, throat discomfort, shortness of breath, etc.

Cough check

Because cough is a non-specific symptom of many diseases, a detailed clinical history, comprehensive examination, chest X-ray or CT, airway reactivity measurement, lung function, electrocardiogram, fiberbronchoscope, and some special Check to rule out other conditions that can cause chronic, refractory cough.

Ordinary X-rays can detect most lung lesions, and sometimes their properties can be determined according to the location, scope and shape of the lesions, such as pneumonia, lung abscess, lung cyst, tuberculosis, lung cancer, pneumoconiosis, etc. X-ray tomography, CT, MRI examinations, and CT scans are advantageous for deep lesions because the cross-sectional images have no image overlap, and lesions that cannot be displayed on X-ray chest radiographs can be found.

Bronchography can directly diagnose the location and shape of bronchiectasis, and it can also indirectly diagnose bronchial lung cancer. Patients with diaphragmatic hernia must be diagnosed with a barium meal. Bronchoscopy can diagnose foreign bodies in the bronchus, bronchial tuberculosis, and bronchial tumors; mediastinoscopy can help diagnose mediastinal tumors and detect mediastinal lymphadenopathy.

Cough diagnosis

Symptoms and the nature of the cough can be helpful in suggesting diagnostic clues.

Accompanied by symptoms

(1) Patients with cough accompanied by high fever should consider acute infectious disease, acute exudative pleurisy, or empyema.

(2) Cough accompanied by chest pain Those with cough accompanied by significant chest pain should consider pleural disease, or diseases of the lungs and other organs, such as lung cancer, pneumonia, and pulmonary infarction.

(3) Cough with sputum and cough with yellow sputum should consider bronchitis and pneumonia; if cough is large, consider lung abscess, bronchiectasis, secondary infection of lung cyst, etc. If cough is accompanied by cough jam-colored sputum, consider pulmonary amoebiasis and pulmonary fluke disease.

(4) Cough accompanied by hemoptysis and hemoptysis should consider bronchiectasis or hollow tuberculosis, and small amount of hemoptysis or blood in sputum should consider lung cancer and tuberculosis.

2. Laboratory inspection

Understanding the amount, color, odor, and nature of sputum is diagnostic. Bronchial casts, pulmonary stones, and sulfur particles were found in sputum, which were helpful for pneumococcal pneumonia, tuberculosis, and pulmonary actinomycosis. A sputum microscopic examination found K. schmannii and Charanite crystals were helpful for patients with bronchial asthma. The discovery of parasite eggs in sputum can diagnose pulmonary fluke disease, and the discovery of hydatid head of cysticercus can diagnose pulmonary cysticercosis. Finding amoeba trophozoites can diagnose pulmonary amoebiasis, etc. Bacterial examination of sputum (smear, culture, animal inoculation) is of great significance for tuberculosis, pulmonary fungal disease, etc .; cancer cells found in sputum can clearly identify bronchial lung cancer Diagnosis; tuberculin test has certain significance for childhood lymph node tuberculosis.

Differential Cough Diagnosis

Should be distinguished from:

Persistent cough

This cough is a precursor to lung disease. This cough will take two to three months to heal once it starts, and no cough medicine seems to do anything about it.

2. Spastic cough

It manifests as a severe cough, with a coughing sound, a cough that can last from a dozen to tens of sounds for a long time. When the cough is flushed, the breathing is affected, and deep breathing is often required after the cough is paused. Severe cough often causes glottic spasm, and sounds like chickens. Continuous and severe cough often causes retching. After a while of coughing, it is a little quiet for a while, and then starts coughing again, which can cause children's tongue ulcers and subconjunctival bleeding. In severe cases, umbilical hernia, inguinal hernia, and prolapse of the anus due to increased abdominal pressure during cough. Spastic cough is common in pertussis, parapertussis, and some adenovirus infections. If there is obvious spasm, the peripheral blood counts of white blood cells and lymphocytes are significantly increased, and a clinical diagnosis of pertussis can be made. Coupled with a positive bacterial culture or a serological immunology, PCR test can confirm the diagnosis of pertussis.

3. Wet cough

A cough accompanied by sputum is called a wet cough. Can be found in pneumonia, bronchitis, bronchiectasis, lung abscess, fibrous cavity tuberculosis and so on. In the early stage, it is mild dry cough, and then it turns into wet cough, with sputum or yellow pus, and early cold symptoms such as fever, sneezing, runny nose, and throat discomfort.

4. Dry cough

No sputum or very little sputum when coughing. Can be found in acute pharyngitis, bronchitis, early tuberculosis, pleurisy and so on.

5. Allergic cough

Paroxysmal refers to intermittent occurrence, there is no persistent state. Paroxysmal cough is a description of a form of seizure. In fact, paroxysmal cough is mostly an allergic cough and should be distinguished from cough variant asthma.

6. Allergic cough

Allergic cough is mostly caused by the unsustainable post-virus infection and bacterial infection, and allergic factors are involved.

Cough treatment

In the treatment of cough, first find out the cause, based on the treatment of the primary disease, choose the appropriate antitussive and expectorant, pay attention to care. When the respiratory mucosa is stimulated by foreign bodies, inflammation, secretions, or allergic factors, it causes reflexes to cough, which helps to exclude foreign bodies or secretions that invade the respiratory tract from the outside, and eliminates respiratory tract irritants. The center of refractory cough can be selected The antitussive achieves the purpose of cough. If the amount of sputum is too large, the cough medicine should not be used alone.

Cough prevention

Most coughs are caused by respiratory diseases, so prevention of respiratory diseases is the key to preventing cough.

1. Strengthen exercise, do more outdoor activities, improve the body's disease resistance.

2. Add or remove clothes in a timely manner during climate change to prevent it from being too cold or overheating.

3. Take less children to crowded public places, less contact with cough patients, reduce the chance of infection.

4. Always open windows to circulate fresh air.

5. Receive timely vaccination to reduce the incidence of infectious diseases.

6. Chinese medicine can be taken during cold epidemic prevention. Use Guanzhong, windproof, nepeta, one post a day, and even serve 2 to 3 days. Children who are often prone to colds can substitute astragalus, red dates, and decoction for tea every day. Long-term use can increase the body's immunity and reduce the occurrence of colds.

7. It is very important to prevent cough and cold. Children should pay attention to exercise and improve their ability to prevent "evil" and avoid external sensations in order to prevent aggravating the illness.

8. Strengthen children's life conditioning, proper diet, and ensure sleep.

9. Usually eat pears and radishes properly, which has a certain preventive effect on cough.

10. Middle-aged and elderly people who have a long-term cough should go to the hospital for examination as soon as possible to determine the cause and promptly treat it.