What can be detected by chest X-ray during physical examination

During a physical examination, chest X-rays can detect diseases such as pneumonia, tuberculosis, emphysema, pleural effusion, and cardiac enlargement. Chest X-ray is mainly used to screen for common lesions in the lungs and heart, and to assist in diagnosis through imaging features.

1. Pneumonia

Chest X-ray can show patchy or large shadows in the lungs, indicating infectious lesions in the lungs. Bacterial pneumonia often presents as consolidation of lung lobes or segments, while viral pneumonia often presents as interstitial changes. If ground glass opacities are found, be alert to atypical pathogen infections. The patient may experience symptoms such as fever, cough, and sputum production, and further clarification of the cause should be obtained through blood routine tests.

2. Pulmonary tuberculosis

Chest X-ray can detect typical lesions in the posterior segment of the upper lobe or the dorsal segment of the lower lobe of pulmonary tuberculosis, manifested as infiltration, fibrosis, calcification, or cavity formation. Active tuberculosis often presents with patchy shadows accompanied by satellite lesions, while old tuberculosis shows fibrous cord shadows. The patient may experience symptoms of tuberculosis poisoning such as low-grade fever, night sweats, and weight loss. Diagnosis requires sputum smear for acid fast bacteria or molecular biology testing.

3. Emphysema

Chest X-ray shows increased lung field transparency, widened intercostal spaces, low diaphragm, and other manifestations of excessive lung inflation. In severe cases, barrel chest may appear. Lobular central emphysema is often accompanied by the formation of pulmonary bullae, while lobular emphysema presents as diffuse changes. Long term smokers who experience post activity shortness of breath should undergo comprehensive lung function tests to assess the degree of airflow limitation.

4. Pleural effusion

Chest X-ray shows dullness of the costophrenic angle or uniform dense shadows in the middle and lower lung fields. When there is a large amount of effusion, the mediastinum shifts to the healthy side. The exudate is mostly symmetrically distributed on both sides, and it is often unilateral and may be accompanied by pleural thickening. Patients may have symptoms such as chest tightness and difficulty breathing, and ultrasound-guided thoracentesis can clarify the nature of the fluid accumulation.

5. Cardiac enlargement

Chest X-ray evaluates heart size by measuring the cardiothoracic ratio, with a value exceeding 0.5 indicating cardiac enlargement. Left ventricular enlargement is characterized by the apex extending downwards to the left, while right ventricular enlargement shows the disappearance of the precordial space. Hypertensive heart disease, dilated cardiomyopathy, and other conditions can all lead to heart enlargement, which requires further differentiation through electrocardiography and echocardiography. When abnormal chest X-rays are found during a physical examination, it is recommended to seek medical attention promptly at the respiratory or cardiovascular department. The doctor will develop a follow-up examination plan based on the imaging findings and clinical symptoms. Smoking and exposure to secondhand smoke should be avoided in daily life, and attention should be paid to keeping warm to prevent respiratory infections. Moderate exercise can enhance cardiovascular function. Individuals aged 40 and above or those with a history of chronic diseases should undergo regular chest imaging examinations.