In the method of general physical examination, percussion sound is very critical. Many patients are not clear about how the abnormal percussion sound of the lung is caused. Let’s understand it together below.

Etiology system

(One) Abnormal dullness in the lung

1. Lung parenchymal disease is common in the early stage of pneumonia exudation, early stage of lung abscess, pulmonary tuberculosis, pulmonary infarction, pulmonary edema, and large-scale pulmonary fibrosis, etc. The etiology is due to bronchial inflammation, serous exudation, and pulmonary fibrosis leading to pulmonary sclerosis, which reduces the lung tissue’s oxygen supply and causes the percussion sound to become turbid.

2。支气管炎堵塞变病如肺良、恶变肿瘤、异物、痰栓造成的一部分叶、段支气管炎彻底堵塞而造成 的阻塞性肺气肿肺不张。因为气管堵塞，部分换气欠佳或彻底不可以换气，使肺组织古供气量降低，支气管萎陷，而造成叩诊音变浊。此外因为支气管炎堵塞继发性的阻塞性肺炎，也可以使肺组织含供气量降低而造成叩诊音变浊。

3。胸膜增厚和胸骨变病少或中测胸腔积液、轻中度胸膜肥厚、胸骨水肿、胸骨肿瘤等，因影响叩诊音传输而造成叩诊音变浊。

15. 2. Obstructive lung atelectasis caused by bronchitis obstruction, such as partial or complete obstruction of segmental bronchitis caused by benign and malignant lung tumors, foreign bodies, sputum plugs, etc., resulting in obstructive lung atelectasis. Due to bronchial obstruction, part of the ventilation is poor or completely impossible, causing the lung tissue to have a reduced air supply, bronchial atrophy, and resulting in a dull percussion sound. In addition, secondary obstructive pneumonia due to bronchitis obstruction can also reduce the air supply of lung tissue and cause the percussion sound to become dull.

14. 3. Thickenings and diseases of the sternum, such as mild to moderate pleural effusion, mild to moderate pleural thickening, edema of the sternum, and sternum tumors, may cause percussion sound to become dull due to the impact on the transmission of percussion sound.

13. (Two) Abnormal flatness in the lungs

12. Abnormal flatness in the lungs is commonly seen in the further development of the above diseases, such as the consolidation phase of lobar pneumonia, massive pulmonary infarction, complete atelectasis on one side, a large amount of pleural effusion, and thickening of the pleura, etc., due to the absence of lung tissue or a significant impact on the transmission of percussion sound, resulting in actual sound.

11. (Three) Hyperresonance in the lungs

10. 1. Hyperresonance in both lungs

9. Commonly seen in various causes of diffuse pulmonary emphysema. The causes are often COPD, bronchial asthma, advanced pulmonary tuberculosis, silicosis, bronchiectasis, etc., combined with emphysema; senile emphysema; congenital alpha-antitrypsin deficiency emphysema, etc. At this time, the lung percussion sound is diffuse hyperresonance, which is due to the weakening of lung support and the increase in air supply.

8. 2. One-sided hyperresonance is commonly seen in compensatory emphysema. For various reasons, such as one-sided atelectasis, damaged lung, one-sided lung resection, severe pleural thickening leading to diaphragmatic collapse, etc., the compensatory lung tissue on the other side may breathe excessively, leading to compensatory emphysema, and the percussion sound on the compensatory side is hyperresonant.

7. 1. Pneumothorax due to the accumulation of a large amount of gas in the pleural cavity, causing lung tissue to collapse or atrophy, and the affected side of the percussion sound becomes tympanic. (Four) Abnormal tympany in the lungs

6. Diaphragmatic hernia may cause abnormal tympany due to the herniation of intraperitoneal organs such as the stomach into the thoracic cavity.

What is the normal percussion sound of the lungs?

What is the normal percussion sound of the lungs?

Routine physical examination of the lungs is very important, which is divided into visual examination, palpation, percussion, and lung auscultation.

The normal percussion sound of the lungs should be clear. If there is pleural effusion or tumor in the lungs, it may produce dullness or flatness. If there is spontaneous pneumothorax in the lungs, percussion may produce tympany. If the patient is suffering from chronic obstructive pulmonary disease (COPD) and emphysema, percussion may produce hyperresonance.

Routine physical examination of the lungs is very important, especially percussion. If percussion reveals hyperresonance, dullness, flatness, or tympany, the patient should be advised to go to the hospital for chest X-ray, chest CT, chest ultrasound, and other examinations to further confirm the diagnosis.