What is a cough? Do you really know?

Coughing is a very common phenomenon in life. It is not a disease, but it will affect people's life and work. There are many reasons for coughing. Colds and fevers may cause coughing. What are the general symptoms of coughing?

Symptoms and signs:

1. Nature of cough Coughing without sputum or with very little sputum is called a dry cough. Dry cough or irritating cough is common in acute or chronic pharyngitis, laryngeal cancer, early stage of acute bronchitis, tracheal compression, bronchial foreign bodies, bronchial tumors, pleural diseases, primary pulmonary hypertension and mitral stenosis. Coughing with sputum is called wet cough, which is common in chronic bronchitis, bronchiectasis, pneumonia, lung abscess and cavitary tuberculosis.

2. Timing and regularity of coughing: Sudden coughing is often caused by inhalation of irritating gases or foreign objects, lymph nodes or tumors compressing the trachea or bronchial bifurcation. Paroxysmal cough can be seen in whooping cough, endobronchial tuberculosis, and bronchial asthma (variant asthma) with cough as the main symptom. Long-term chronic cough is more common in chronic bronchitis, bronchiectasis, lung abscess and tuberculosis. Night cough is common in patients with left heart failure and pulmonary tuberculosis. The cause of night cough may be related to the aggravation of pulmonary congestion at night and increased vagus nerve excitability.

3. The timbre of a cough refers to the characteristics of the sound of a cough. For example, ① a hoarse cough is mostly caused by inflammation of the vocal cords or tumors compressing the recurrent laryngeal nerve; ② a cockcrow-like cough is characterized by continuous paroxysmal coughs accompanied by high-pitched inspiratory echoes, which are often seen in whooping cough, epiglottis, laryngeal diseases or tracheal compression; ③ a metallic cough is common in coughs caused by direct compression of the trachea by mediastinal tumors, aortic aneurysms or bronchial cancer; ④ a low or weak cough is seen in patients with severe emphysema, vocal cord paralysis and extreme weakness.

Pathological causes:

1. Inhaled substances Inhaled substances are divided into two types: specific and nonspecific. The former include dust mites, pollen, fungi, animal dander, etc.; non-specific inhalants include sulfuric acid, sulfur dioxide, chloramine, etc. Specific inhalants of occupational cough include toluene diisocyanate, phthalic anhydride, ethylenediamine, penicillin, protease, amylase, silk, animal dander or excrement, etc. In addition, non-specific ones include formaldehyde, formic acid, etc.

2. Infection

The development and onset of cough are associated with recurrent respiratory tract infections. Patients with cough may have specific IgE to bacteria, viruses, mycoplasma, etc., and inhalation of the corresponding antigens may induce coughing. After viral infection, the respiratory epithelium can be directly damaged, resulting in increased respiratory tract reactivity. Some scholars believe that interferon and IL-1 produced by viral infection increase the histamine released by alkaliphilic granulocytes. During the infant period, many children develop cough symptoms after being infected by respiratory viruses (especially respiratory syncytial virus). Coughing caused by parasites such as roundworms and hookworms is still seen in rural areas.

3. Food

Cough attacks caused by diet are common in cough patients, especially infants and young children who are prone to food allergies, but this phenomenon gradually decreases with age. The most common foods that cause allergies are fish, shrimp, crab, eggs, milk, etc.

4. Climate change

Changes in air temperature, air pressure and/or ions in the air can induce coughing, so it is more common in cold seasons or when the climate changes from autumn to winter.

5. Mental factors

The patient's emotional excitement, nervousness, resentment, etc. can all trigger a coughing attack. It is generally believed that it is caused by cerebral cortex and vagus nerve reflexes or hyperventilation.

6. Exercise

About 70% to 80% of cough patients develop cough after strenuous exercise, which is called exercise-induced cough or exercise cough. Clinical manifestations include cough, chest tightness, shortness of breath, wheezing, and wheezing can be heard by auscultation. Although some patients do not have typical asthma symptoms after exercise, lung function tests before and after exercise can reveal bronchospasm.