Constant cough? Understand sputum changes and easily identify potential diseases

Author: Jiang Guanchao, Chief Physician, Peking University People's Hospital

Reviewer: Zhi Xiuyi, Chief Physician, Xuanwu Hospital, Capital Medical University

Coughing is a reflex action of the human body to protect itself, aiming to clear foreign matter or secretions from the respiratory tract. However, when coughing occurs frequently or is accompanied by coughing up phlegm, it may be a sign of a disease. The color, properties and amount of phlegm coughed up can often provide doctors with valuable diagnostic clues.

The causes of cough and sputum are complex and varied. They are not only directly related to the respiratory system, but may also involve systemic diseases. The most common are respiratory infections, such as tracheitis, bronchitis and pneumonia. These diseases can directly irritate the respiratory mucosa, causing coughs and promoting the secretion and discharge of sputum. In addition, asthma, a non-specific airway inflammation caused by allergies, also has cough as one of the main symptoms. It is worth noting that lung cancer is also a common cause of cough, especially when lung cancer grows into the airway, it is more likely to cause irritating coughs and even hemoptysis.

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We need to carefully analyze the symptoms of coughing and sputum in different situations.

1. Chronic bronchitis in the elderly

Chronic bronchitis is a common chronic disease among the elderly. Patients often experience coughing, sputum, and wheezing for more than three months each year for two consecutive years, and these symptoms are particularly obvious when the seasons change. The sputum of patients with chronic bronchitis is mostly white and foamy, without yellow sputum and fever. In acute attacks, yellow sputum and fever may occur. For such patients, chest X-rays or chest CT scans often show thickening and weight gain of the lung texture, while routine blood tests may show no obvious abnormalities.

2. Bronchiectasis and purulent sputum

When patients have a large amount of purulent sputum with a foul odor, they should be highly alert to the possibility of bronchiectasis. Bronchiectasis is a bronchial disease caused by lung infection, characterized by repeated coughing, large amounts of purulent sputum, and hemoptysis. Due to repeated aggravation of infection, sputum may appear yellow-green, indicating infection with Pseudomonas aeruginosa or Staphylococcus aureus. For patients with bronchiectasis who are ineffective with medical treatment, have recurrent episodes, and have limited lesions, surgical resection of the diseased lung segment or lobe is an effective treatment.

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3. Cough with fever and yellow sputum

Cough with fever and yellow sputum is a typical manifestation of acute infection, which is common in pneumonia or terminal bronchiolitis. At this time, anti-infection treatment is particularly important. Chest CT combined with routine blood tests can help confirm the diagnosis and assess the severity and scope of the infection.

4. Irritating dry cough and variant asthma

An irritating dry cough, especially when aggravated by cold air or odors, and more severe at night, often indicates variant asthma. Variant asthma has cough as the main or only symptom, without obvious wheezing and dyspnea. For such patients, they should see a respiratory physician and receive asthma-related treatment.

5. Irritating dry cough with blood and malignant tumors

An irritating dry cough with blood streaks is one of the warning signs of malignant tumors. When lung cancer grows into the airway, violent coughing may cause small blood vessels to rupture, leading to hemoptysis or blood-streaked sputum. At this time, you should seek medical attention in time and undergo a chest CT scan to rule out the possibility of lung cancer.

Medical examinations play a vital role in the diagnosis process. Doctors usually arrange a chest X-ray first to get a preliminary understanding of the lung condition. If further diagnosis is needed, chest CT is an indispensable examination method, which can provide more detailed and accurate lung imaging information. For patients with suspected airway lesions, fiberoptic bronchoscopy can be used to directly observe the lesions in the trachea and bronchi, and biopsy samples can be taken for pathological examination. In addition, auxiliary examinations such as allergen testing can also help to clarify the diagnosis of diseases such as variant asthma.