The diagnosis of pulmonary diseases is a systematic process that combines various methods such as clinical observation, imaging examinations, and laboratory analyses. Doctors will initially assess possible causes through medical history collection, symptom evaluation, and physical examination, and then arrange specialized tests based on the suspected diagnosis. Early diagnosis not only improves the success rate of treatment but also effectively delays disease progression.
The diagnostic process typically begins with the patient's basic symptoms, such as the nature and duration of chronic cough, shortness of breath, or chest pain. Doctors will further inquire about the patient's exposure history, such as smoking habits, occupational environment, or family medical history, as this information helps narrow down the possible range of diseases. Modern medical technology provides various high-resolution imaging and functional tests that can accurately assess structural and functional abnormalities in the lungs.
Clinical evaluation is the foundation of diagnosis, where doctors first conduct a detailed medical history inquiry. This includes the onset time of symptoms, changes in severity, and whether other symptoms such as hemoptysis or weight loss accompany them. For example, chronic cough with yellow-green sputum may indicate chronic obstructive pulmonary disease (COPD), while sudden onset of shortness of breath may be related to pneumothorax.
In physical examination, the stethoscope is a key tool. Doctors will carefully listen to breath sounds, wheezing, or crackles, as the characteristics of these sounds can suggest specific lesions. For instance, widespread wheezing may be seen in asthma, while localized crackles may reflect localized pulmonary edema or infection.
Imaging examinations are central to the diagnosis of pulmonary diseases. Chest X-rays can quickly reveal large-scale abnormalities such as pneumonia, lung atrophy, or tumors, while high-resolution computed tomography (HRCT) can precisely show changes in alveolar structure, such as the reticular pattern in interstitial pneumonia or emphysema. Pulmonary function tests (PFTs) directly assess ventilation function, with a blockage index (FEV1/FVC) below 70% commonly seen in obstructive airway diseases.
Invasive examinations such as bronchoscopy allow direct observation of the airways and collection of tissue samples. Bronchoscopy combined with brushing or biopsy can diagnose lung cancer or infectious pathogens. Blood tests are used to assess inflammatory markers (such as C-reactive protein), blood gas analysis, or specific antibodies (such as tuberculin tests).
Screening tools are common in high-risk groups, such as long-term smokers undergoing low-dose computed tomography to detect lung cancer early. Questionnaire tools like the COPD Assessment Test (CAT) quantify the impact of symptoms on quality of life, assisting in staging and treatment choices. Biomarkers such as serum CYFRA21-1 levels can aid in monitoring lung cancer progression.
Differential diagnosis requires ruling out diseases with similar symptoms. For example, distinguishing asthma from psychogenic dyspnea requires combining pulmonary function tests and electrocardiograms. Shortness of breath from pulmonary embolism and heart failure needs differentiation through D-dimer blood tests and ultrasound examinations.
Imaging differentiation is common in distinguishing tumors from infections. Benign nodules and malignant tumors differ in shape and growth rate on CT images, and radiologists will assess risk based on classification systems such as "LI-RADS." Chronic cough may be caused by gastroesophageal reflux or post-nasal drip, requiring 24-hour pH monitoring or nasal endoscopy for confirmation.
Early diagnosis can significantly improve prognosis. For instance, stage I lung cancer patients have a 5-year survival rate of up to 70% after surgical resection, while treatment options for late-stage metastatic patients are extremely limited. Early use of inhalers in chronic obstructive pulmonary disease (COPD) can slow the decline in lung function, preventing progression to respiratory failure.
Early detection of infectious pathogens can prevent the spread of complications. For example, early use of anti-tuberculosis drugs for tuberculosis can lead to complete recovery, while delayed diagnosis may result in extensive pulmonary fibrosis or systemic dissemination. Regular health check-ups can help high-risk groups detect abnormalities before symptoms appear, such as arranging examinations when chronic cough or unexplained weight loss occurs.
Chest X-rays can observe structural abnormalities in the lungs, such as fluid accumulation or nodules, but cannot directly assess lung ventilation function. Combining pulmonary function tests allows for understanding the degree of airway obstruction and lung expansion capability, helping to differentiate between various types of diseases such as asthma and emphysema, ensuring a comprehensive diagnosis.
What test results in smokers might be particularly affected by smoking duration and require special attention in the diagnosis of pulmonary diseases?Long-term smokers often exhibit a decline in pulmonary function indices, such as abnormal forced expiratory volume in the first second (FEV1). Doctors will determine whether the decline in lung function is due to natural aging or disease based on smoking duration and exposure time, and will use high-resolution computed tomography (HRCT) to rule out conditions such as smoke-induced lung disease or fibrosis.
If a lung CT shows abnormal shadows but there are no symptoms, is immediate treatment necessary?When asymptomatic but a shadow is found on CT, doctors will assess the risk based on the shape, size, and growth rate of the shadow. If a benign nodule is suspected and is less than 8 mm in diameter, regular follow-up may be recommended; if the shape is irregular or it grows rapidly, further biopsy or biomarker tests are needed to rule out malignant lesions.
What preparations should be noted before and after pulmonary function tests to ensure accurate results?Patients should avoid smoking for 24 hours before the test and refrain from using bronchodilators to prevent affecting the test results. During the test, patients need to follow instructions to exhale forcefully and repeat the actions to ensure test consistency. Those with abnormal results may need to undergo blood tests or arterial blood gas analysis to confirm whether gas exchange function is abnormal.
When is bronchoscopy necessary? How is the risk of invasive examinations assessed?When imaging examinations reveal unknown shadows, recurrent infections, or suspected central lung cancer, bronchoscopy is needed to obtain tissue samples. The risks of the examination include laryngeal discomfort or minor bleeding, but modern endoscopic techniques have significantly reduced complications. High-risk patients (such as those with coagulation disorders) will have their bleeding risk assessed before making a decision.
%201.svg)
Copyright © 2025 MedFrontiers. All Rights Reserved.
